Developer & DevOps

Bash cheat sheet — 100+ commands & idioms for variables, conditionals, loops, functions, pipes, traps, with real one-liners.

awk + sed cheat sheet — 80+ one-liners for text processing, with real examples and common pitfalls.

Vim cheat sheet — 100+ commands covering modes, motions, edits, search, registers, splits, with mnemonics.

curl cheat sheet — 80+ curl commands for GET/POST/auth/upload/download/SSL/proxy, with real examples and pitfalls.

Git command cheat sheet — searchable, with explanations, common mistakes, and real examples.

Docker command cheat sheet — 80+ commands with real examples, common mistakes, and Compose section.

kubectl cheat sheet — 100+ Kubernetes commands with real examples, common pitfalls, and YAML snippets.

Nginx cheat sheet — common configs, location/server blocks, SSL, reverse proxy, gzip, real examples & gotchas.

AWS CLI cheat sheet — 80+ commands for EC2 / S3 / IAM / Lambda / RDS / EKS / CloudFormation with real examples.

Python cheat sheet — 100+ idiomatic Python snippets for string, list, dict, file, async, with real examples.

Go (Golang) cheat sheet — 100+ idiomatic snippets covering syntax, goroutines, channels, generics, errors, stdlib.

Rust cheat sheet — 100+ snippets covering ownership, borrowing, lifetimes, traits, async, error handling.

TypeScript cheat sheet — 100+ snippets for types, generics, utility types, narrowing, async patterns.

React hooks cheat sheet — all 17 built-in hooks (useState / useEffect / useMemo / useTransition / useFormStatus...) with real examples and pitfalls.

Next.js 15 cheat sheet — App Router, Server Components, Server Actions, dynamic routes, with examples and pitfalls.

Vue 3 cheat sheet — Composition API, reactivity, components, directives, Pinia, with side-by-side Options API comparison.

Svelte 5 cheat sheet — runes ($state, $derived, $effect), snippets, props, stores, with Svelte 4 comparison.

Tailwind CSS cheat sheet — 100+ utility classes (spacing, color, flex, grid, typography, responsive) with live preview.

npm / yarn / pnpm cheat sheet — 80+ commands across init, install, scripts, publish, with cross-tool comparison.

Markdown syntax cheat sheet — every rule with live preview side by side, GFM + flavors.

SQL cheat sheet — 100+ statements covering SELECT, JOIN, window functions, indexing, MySQL/PostgreSQL/SQLite differences.

Redis cheat sheet — 80+ commands across strings, hashes, lists, sets, sorted sets, pub/sub, streams, scripts, with examples and pitfalls.

MongoDB cheat sheet — 80+ shell commands & query operators for CRUD, aggregation, indexing, replication.

PostgreSQL cheat sheet — 80+ commands & functions for psql, JSONB, CTEs, window functions, indexing, partitioning, advanced extensions.

Elasticsearch cheat sheet — 80+ Query DSL, mapping, analyzer, aggregation, replication, with real examples.

Interactive regex cheat sheet — quick reference for every flavor (JS, Python, PCRE).

HTTP status code explorer — all 70+ codes with meaning, common causes, real examples, and what to check.

DNS record explainer — all 18 common record types (A, AAAA, CNAME, MX, TXT, SRV, etc.) with syntax, examples, and gotchas.

800+ everyday chengyu — pinyin, origin, usage.

Apache HTTP Server cheatsheet for httpd.conf, VirtualHost, .htaccess, mod_rewrite, SSL, proxying, auth, headers, and logs.

Search rate-limit headers, retry rules, provider quirks, and paste 429 headers to decode the next safe retry

Complete 0–127 ASCII table: decimal, hex, octal, binary, character, name, HTML entity and escape — control codes explained, click to copy, fully searchable.

Search AWS IAM policy fields, ARNs, conditions, managed policies, trust rules, and inspect policy JSON locally.

AWS S3 cheat sheet — 58+ commands covering buckets, sync, presign, versioning, lifecycle, encryption, CORS, and multipart.

Cloudflare DNS cheat sheet with proxy rules, TTL notes, CNAME flattening, mail records, and a local record checker

TCP/UDP port cheat sheet, 60+ services, search by number or name, copy in one click, browser-only

Every HTTP status code 1xx to 5xx with meaning, when-to-use and RFC, search by code or keyword, browser-only

File extension ⇄ MIME type lookup — 130+ types, both directions, copy the exact Content-Type — browser-only

Format, validate, and minify JSON instantly — right in your browser.

Pretty-print, minify, and validate XML in your browser — preserves CDATA, comments, and namespaces.

Format and beautify YAML — re-indent, validate, minify, sort keys.

Format and beautify SQL — supports MySQL, PostgreSQL, BigQuery, SQLite and 17 more dialects.

Format and beautify CSS — sort properties, indent rules, expand or minify.

Format and validate INI / TOML-like config — sort sections, align equal signs.

Minify HTML — strip comments, whitespace, optional attributes, inline CSS/JS. 40-60% smaller.

Minify CSS — strip comments, whitespace, shorten colors, merge selectors. 30-60% smaller.

Minify JavaScript — strip comments, whitespace, optional name shortening. 40-70% smaller.

Lightly obfuscate JavaScript in the browser: strip comments, remove debugger/console calls, and optionally wrap strings with base64.

Minify JSON into a compact single line, optionally sort object keys, and keep everything local.

Validate JSONL line by line, pretty-print it, convert to a JSON array, or export a CSV-like table locally.

JSON to TypeScript interface — paste JSON, get clean interfaces with union types from arrays, optional vs required detection, root name customizable.

Paste JSON or NDJSON samples and infer a Draft 2020-12 style schema with types, required fields, formats, enums, and examples.

TOML formatter + converter — format/validate TOML 1.0, convert TOML ↔ JSON ↔ YAML, with error line/column.

GraphQL formatter + minifier — beautify query/mutation/subscription/schema, validate syntax, copy minified single-line for HTTP body.

Audit OpenAPI JSON or YAML for endpoint coverage, missing operation IDs, security gaps, and weak response documentation.

Inspect package-lock.json, pnpm-lock.yaml, or yarn.lock for duplicate versions, risky sources, prereleases, and missing integrity.

Convert Markdown to clean HTML — headings, lists, code, links, images, tables — instant live preview, browser-only

HTML to Markdown — paste rich content, get clean .md with links, code, tables, lists preserved.

Markdown editor with live split-pane preview — GFM tables, fenced code with syntax highlight, math, emoji, table of contents, export as HTML / PDF-ready.

Build Markdown tables visually — add/remove rows, column alignment, paste from Excel / CSV — browser-only

Convert CSV to JSON or JSON to CSV — handles quoted commas, newlines in cells, custom delimiter — browser-only

Convert uploaded or pasted CSV into clean Markdown tables with quoted-cell support, locally in the browser.

Convert CSV files to tab-separated values while preserving quoted commas, quotes, and multiline cells locally.

Turn tab-separated files into standards-friendly CSV with proper quoting, download, and local processing.

Remove duplicate CSV rows by full row or selected key columns from uploaded files, locally and safely.

Upload or paste CSV, keep only selected columns by name or index, and export a smaller privacy-safe file.

Sort uploaded CSV rows by a selected column with numeric-aware ordering and local-only processing.

Filter uploaded CSV rows by column value using contains, equals, or regex, with local browser processing.

Flip CSV rows and columns from uploaded files or pasted data, with ragged-row handling and local output.

Standardize CSV header rows to snake_case, kebab-case, camelCase, or Title Case before imports and scripts.

Upload CSV and get a quick Markdown profile of filled, missing, unique, numeric, min, max, and average values.

Upload CSV or TSV and profile missing values, inferred types, invalid cells, duplicate rows, whitespace issues, top values, and numeric outliers.

Triage a mixed batch locally for file type mismatches, duplicate candidates, metadata privacy, archive risks, and next-step tools.

Upload files and inspect filename, size, browser MIME type, extension, and magic-byte signature locally.

Upload or paste text and convert CRLF, CR, and LF endings to a consistent LF or CRLF output locally.

Upload a text file and remove BOM, null bytes, trailing spaces, and excessive final blank lines locally.

Upload Markdown and extract inline links, reference links, images, and bare URLs into a local CSV.

Upload HTML and extract anchors, images, scripts, stylesheets, canonicals, and meta URLs into CSV locally.

Upload a batch, generate safe new filenames with sequence numbers and case rules, then export a CSV plan.

Upload PDFs and extract document metadata, page-count hints, encryption flags, and producer details locally.

Inspect PDF MediaBox and CropBox dimensions to catch mixed page sizes before print, merge, or upload.

Inspect DOCX, XLSX, and PPTX package structure for macros, media, embedded objects, custom XML, and size hotspots.

Read a ZIP central directory locally and flag traversal paths, encryption, duplicate names, and risky ratios.

Upload TTF or OTF files and extract family names, PostScript names, version, units per em, glyph count, and table list.

XML to JSON converter — preserves attributes, nested elements, CDATA. Reversible.

Convert between YAML and JSON — both directions, pretty-printed, error messages with line numbers — browser-only

Paste CSV or TSV, get a monospace table that lines up: +--+ ASCII, Unicode box, Markdown, with real CJK width

Turn CSV into CREATE TABLE + INSERT statements — type inference, safe value escaping, MySQL / PostgreSQL / SQLite — browser-only

Turn a CSV table into clean, indented XML — name the root and row elements, columns as elements or attributes, escaped output. Browser-only.

Turn an indented file list into a clean ASCII folder tree with box-drawing guides, choose Unicode or ASCII, then copy it into any README, browser-only

Milliseconds or seconds into 2d 3h 5m 10s, 2 days 3 hours, and 3 hours ago, bilingual, copy in one click, browser-only

Beautify minified or messy HTML into clean indented markup, browser-only

Structural JSON compare — added / removed / changed keys by path, three-colour tree, browser-only

Flatten nested JSON to dot-notation keys and unflatten it back — choose the delimiter and array style, types preserved, browser-only.

Deep-merge two or more JSON objects in the browser, with array strategy and prototype-pollution guard

Paste a JSON sample, get a typed JSON Schema (draft-07 or 2020-12) in your browser

Sort JSON object keys alphabetically, recurse into nested objects, asc or desc, values untouched, runs in your browser

Escape raw text into JSON string content or a quoted JSON string literal, and decode escaped JSON strings back to readable text in your browser.

JSON to C# class or record — paste JSON, get PascalCase properties with System.Text.Json or Newtonsoft attributes, nested classes, nullable T?, init setters, DateTime detection.

JSON to Dart / Flutter class — paste JSON, get final fields, camelCase names, factory fromJson, toJson, null-safe T?, nested classes, and optional @JsonSerializable codegen.

JSON to Go struct — paste JSON, get typed structs with json tags, exported fields, nested sub-structs, pointers for nullable, int64 and omitempty options.

JSON to Java POJO, record, or Lombok @Data — paste JSON, get camelCase fields with getters/setters, Jackson @JsonProperty or Gson @SerializedName, nested classes, primitive vs boxed inference.

JSON to Kotlin data class — paste JSON, get val properties, camelCase fields, nullable T?, nested classes, and kotlinx.serialization @SerialName, Gson @SerializedName, or Moshi @Json annotations.

JSON to PHP array — paste JSON, get a clean associative or indexed array with short [] or array() syntax, 2/4 indent, trailing comma, and an optional <?php return …; wrapper.

JSON to Protobuf — paste JSON, get proto3 message definitions with inferred scalar types, incrementing field numbers, snake_case fields, repeated arrays, and named nested messages.

JSON to Python — paste JSON, get @dataclass or Pydantic v2 models with type hints, Optional inference, nested classes, snake_case fields and aliases.

Turn a JSON object into a URL query string — repeat, key[], or comma arrays, bracket-nested objects, sorted, skip-empty — and back to JSON, 100% in your browser

JSON to Rust struct — paste JSON, get serde-derived structs with snake_case fields, serde rename, Option for nullable, Vec for arrays, nested sub-structs.

JSON to Swift Codable — paste JSON, get struct or class types conforming to Codable, camelCase properties, a CodingKeys enum for non-matching keys, Optional T? for nullable fields, and nested types.

Parse a URL query string into JSON and rebuild a query string from JSON — two-way, live, with array + nested object conventions — 100% in your browser

Strip comments and whitespace from SQL — collapse to one compact line, string literals stay untouched, runs entirely in your browser.

Escape & unescape strings for JSON, JS, Java, C, SQL, Shell, HTML, CSV & regex — both directions — browser-only

Convert tabs to spaces and spaces to tabs, real tab-stop alignment, leading-indent or whole-line, all in your browser

See every space, tab, newline and hidden character — middle-dot spaces, arrow tabs, pilcrow line breaks, trailing-space highlight, browser-only

Make JSON greppable. json.users[0].name = "Ada"; one leaf per line, and ungron right back. Runs in your browser.

Compute MD5 / SHA-1 / SHA-256 / SHA-384 / SHA-512 hashes, all five at once, browser-only

Compute SHA-1, SHA-256, SHA-384, or SHA-512 hashes for uploaded files entirely in the browser.

Paste an expected checksum, upload a file, and verify SHA digest matches locally before installing or sharing.

Upload a batch and find exact duplicate files by SHA hash locally, with a Markdown cleanup report.

Upload a small file and convert it to raw Base64 or a data URL locally for embeds, fixtures, and tests.

Paste raw Base64 or a data URL, decode it locally, inspect bytes, and download the reconstructed file.

bcrypt password hash generator + verifier — pick rounds, hash and compare in browser.

Decode JWT header / payload / signature — verify structure, check exp, copy claims — browser-only

Encode JWT — pick algorithm (HS256/HS384/HS512), set header/payload/secret, get token.

Scan .env files, config snippets, and CI logs locally for likely API keys, tokens, private keys, JWTs, and database URLs.

Encode/decode HTML entities — &amp; &lt; &gt; &quot; &#39; and all numeric refs — browser-only

Base32 + Base58 encoder/decoder — RFC 4648 base32 (Crockford variant too), Bitcoin base58, Solana base58, hex/text/file input.

Number base converter — binary, octal, decimal, hex, and any base 2-36. Bitwise too.

HEX ⇄ RGB ⇄ HSL ⇄ HSV ⇄ CMYK — instant 5-way conversion, live swatch — browser-only

Color blindness simulator — paste hex or upload image, see how it looks to people with protanopia / deuteranopia / tritanopia / monochromacy.

Color contrast checker — WCAG 2.2 AA/AAA compliance for normal/large text, real-time grade.

HTML named colors — all 147 CSS color names with hex/RGB/HSL, searchable + sortable.

Generate cryptographically random API keys and secret tokens with a custom prefix, length, and charset, with a live entropy readout, entirely in your browser.

Generate 2FA backup and recovery codes the GitHub way, formatted, unique, and made in your browser

Username plus password into Authorization Basic base64, with curl -u and -H examples, plus reverse decoding, all in your browser

Decimal ⇄ binary coded decimal in 8421 code, with packed view, hex and per-digit nibbles, all in your browser

Add, subtract, multiply and divide two binary numbers, exact BigInt math, results in binary, decimal, hex and octal, browser-only

Left shift, logical and arithmetic right shift — see the bits move, pick 8/16/32-bit, read decimal, hex and binary — browser-only

AND, OR, XOR, NOT and bit shifts on integers, with decimal, hex and binary side by side, all in your browser

Decode JWT headers and payloads locally, inspect registered claims, timing, audience and risk signals.

Enter any positive integer, watch 3n+1 run to 1 — full hailstone sequence, stopping time, and peak, exact via BigInt

Standard CRC-32 (IEEE) of any text in hex and unsigned decimal, with optional CRC32C, computed in your browser

Luhn-valid fake card numbers for payment-integration testing — Visa, Mastercard, Amex, Discover, JCB, Diners — non-real, sandbox-only — browser-side

Read the card network from a number's BIN prefix — Visa, Mastercard, Amex, Discover, JCB, Diners, UnionPay — plus Luhn check, 100% in your browser

Compute or verify the check digit for EAN-13, UPC-A and EAN-8 barcodes, mod-10 weighting with the odd and even positions, browser-only

Emoji ⇄ Unicode code points, both ways. U+XXXX, decimal, HTML entity, JS and CSS escapes, every code point of a ZWJ family, skin tone or flag, plus one-click restore, all in your browser

Exact n! for any non-negative integer, with digit count, trailing zeros, double factorial and scientific notation, computed on BigInt right in your browser

First N terms, a range, or the nth value, with running sum and golden-ratio convergence, exact via BigInt, all in your browser

Latitude/longitude ⇄ geohash, base32, precision 1-12, bounding box and 8 neighbors, all in your browser

Decimal, binary and Gray code three ways, gray = n^(n>>1), one click each side, all in your browser

Encode, decode and error-correct Hamming (SEC / SECDED) codes — syndrome, parity coverage, one-click copy — browser-only

Count the differing positions between two equal-length inputs, in characters, binary bits or integer XOR, all in your browser

Offset, hex bytes and ASCII side by side, the classic xxd / hexdump -C layout, fully in your browser

Check any IBAN with the ISO 7064 mod-97 checksum and a 60-country length table, formatted output, one-click copy, browser-only

Decimal to single and double precision bits, sign exponent mantissa split, full hex and binary, all in your browser

IPv4 dotted-quad to 32-bit integer, binary and hex, both directions, browser-only

Convert ISBN-10 ⇄ ISBN-13 with the check digit recomputed — 978 prefix, mod-10 and mod-11, hyphen-aware, browser-only

Check an ISBN-10 or ISBN-13 check digit and convert between the two, with the X case and 978 prefix handled, all in your browser

Check an 8-digit journal ISSN with the MOD 11 check digit — single or batch, computes the check character, one-click copy, browser-only

Check any number against the Luhn (mod 10) algorithm, see the doubling math step by step, or compute the missing check digit, all in your browser

Random MAC addresses in colon, hyphen, Cisco dotted or bare hex, with locally-administered and unicast bits and optional vendor OUI, all in your browser

Compute a^b mod m with fast exponentiation and BigInt, plus modular inverse and step-by-step squaring, all in your browser

Generate ObjectIds, decode the embedded timestamp, build $gte/$lte bounds for a time range — all in your browser

Check an ORCID iD check digit with ISO 7064 MOD 11-2, complete the check digit from the first 15 digits, validate a whole list, all in your browser

Build an otpauth:// 2FA setup URI from issuer, account and Base32 secret, parse one back, then turn it into a QR code, browser-only

Entropy in bits, full character pool, and brute-force crack time across four attacker speeds, computed locally in your browser

Break any integer into prime factors with exponent form, divisor count and full divisor list, exact BigInt math, browser-only

Turn literal text into a safe regex pattern: a.b becomes a\.b, copy the ready /…/ form, reverse it too, all in your browser

Pull every regex match out of any text, grab a single capture group, dedupe, one per line, copy in one click, all in the browser

Check a 9-digit ABA routing number with the public 3-7-1 checksum, read its Federal Reserve routing symbol, one-click copy, browser-only

Decode a 64-bit Snowflake into timestamp, machine id and sequence, with Twitter, Discord and custom epochs, all in BigInt, browser-only

Base32 secret in, live 6-digit code out, 30s countdown and next code, SHA1/256/512, 100% in-browser, RFC 6238

Signed decimal to two's complement binary and hex at 4, 8, 16, 32, 64 bits, with sign-magnitude and one's-complement steps, runs in your browser

Pull the timestamp and randomness back out of a ULID — decode one or paste many, with UTC, ISO and local time — 100% in your browser

Sortable, URL-safe unique IDs — batch generate, monotonic mode, decode the timestamp back out — 100% in your browser

Count UTF-8 bytes, UTF-16 code units, Unicode code points and characters in any string, right in your browser

Paste a UUID, read back its version, variant and the timestamp baked into the bytes

Namespace UUID from a name via SHA-1 — deterministic, RFC 4122, browser-only

Time-ordered, sortable UUIDs by RFC 9562: batch generate, monotonic mode, decode the embedded timestamp, all in your browser

CSS Grid generator — visually design grid layouts (rows/cols/gap/areas), copy CSS code, fully responsive.

CSS grid visual generator — drag to set columns/rows, place grid-area named regions, copy ready CSS + HTML, with 12 layout templates.

CSS clamp() fluid typography generator — min/max font size, viewport range, full type scale (h1-h6 + body), copy CSS / Tailwind.

CSS font stack generator — system-safe font families with full Win/Mac/Linux/Android/iOS fallback chains, with CJK fallbacks, copy as CSS/Tailwind/SwiftUI.

CSS shadow generator pro — multi-layer box-shadow + text-shadow + filter:drop-shadow, with Material/Tailwind/Apple shadow presets and dark-mode preview.

CSS transform generator — rotate/scale/skew/translate (2D + 3D) with live preview, copy CSS, 12 preset combos.

CSS cubic-bezier editor — drag two control points, preview live with bouncing ball + scaling box + opacity fade, copy CSS / JS / Framer Motion / GSAP / SVG path.

Glassmorphism CSS generator — backdrop-filter blur + transparency + border, live preview with 8 background presets, copy CSS/Tailwind/SwiftUI.

Gradient mesh generator — 4-12 control points with bilinear blend, output as SVG, PNG, CSS multi-radial-gradients fallback for older browsers.

Compress one image to a target KB size locally with quality search, automatic downscaling, preview, and download.

Image resizer — resize JPG/PNG/WebP by pixels/%/preset, fully client-side, no upload.

Image format converter — JPG ↔ PNG ↔ WebP ↔ AVIF, batch + transparent background handling, 100% client-side.

Image cropper — drag to crop, fixed ratios (1:1 / 16:9 / 9:16 / 4:3), zoom, rotate, fully client-side.

Image watermark — text or image watermark with position grid, opacity, tile mode, batch processing.

Inspect PNG, JPEG, GIF, WebP, and SVG dimensions, bit depth, ICC, EXIF, XMP, animation, and notes.

Scan uploaded images for EXIF, GPS, camera, software, dates, XMP, and ICC privacy indicators.

Audit SVG viewBox, dimensions, scripts, external references, styles, ids, classes, title, and desc tags.

Code screenshot generator (Carbon-like) — syntax highlight, beautiful gradient backgrounds, window chrome, export PNG/SVG for X / blog covers.

Image compressor — squeeze JPG/PNG/WebP without server upload, with quality slider, batch mode, file size comparison.

Generate SEO meta tags — title, description, Open Graph, Twitter Card, Schema.org.

QR code decoder — drag a QR image or paste URL, see the text/URL inside, plus phishing & risky-link warnings.

Drop a folder of QR images and get every decoded URL in one table — fast batch audit for packaging, posters, and print runs.

Regex from examples — paste positive matches + negative non-matches, get a regex that hits all positives and rejects all negatives, with multiple candidate patterns ranked by specificity.

Regex visualizer — see your pattern as a railroad diagram + matching state machine, with capture groups highlighted.

Test JavaScript regex live — match highlighting, group capture, replace preview, flag toggles — browser-only

Compare two blocks of text — line-by-line additions, deletions, equal — colour highlighted, browser-only

Convert text between camelCase, snake_case, kebab-case, PascalCase, Title Case, UPPER, lower — instant, browser-only

Turn any title into a clean URL slug — lowercase, dashes, ASCII-safe transliteration, multiline batch — browser-only

Validate emails — RFC 5321 syntax + bulk paste + disposable detection + MX hint.

UTM link builder — track campaign source, medium, name. GA4/Google Analytics compatible.

Generate v4 random, v7 time-ordered, NIL, and Short UUIDs instantly — entirely in your browser.

Generate realistic mock JSON / CSV / SQL data — names, emails, dates, addresses, nested objects.

CSS px ↔ rem ↔ em converter — visual scale, base font size adjustable.

HTML table to CSV converter — paste HTML or full page source, extract all tables, get CSV/TSV/JSON/Excel-ready output with header detection + colspan/rowspan handling.

Upload or paste HTML and extract forms, methods, actions, fields, labels, required flags, autocomplete, password fields, and security risks.

Extract, deduplicate, inspect, copy, and export query parameters from one URL or many URLs locally.

TypeScript to Zod schema converter — paste interface/type, get z.object() schema, supports unions/optionals/nested/generics/enum/Record/Map/Set.

.env file validator — parse Bash-style .env, detect dups / missing required / unsafe values / leaked secret patterns; cross-compare prod / staging / dev envs.

Audit OpenAPI JSON or YAML for endpoint coverage, missing operation IDs, security gaps, and weak response documentation.

Check robots.txt for user-agent groups, allow and disallow rules, sitemap declarations, crawl-delay, and unsupported directives.

Audit raw response headers for HSTS, CSP, cookie flags, MIME sniffing, clickjacking, referrer, and permissions policy gaps.

Inspect Content-Security-Policy directives for unsafe sources, missing fallbacks, framing gaps, object-src, base-uri, and reporting coverage.

Inspect package-lock.json, pnpm-lock.yaml, or yarn.lock for duplicate versions, risky sources, prereleases, and missing integrity.

Scan .env files, config snippets, and CI logs locally for likely API keys, tokens, private keys, JWTs, and database URLs.

Upload a Chrome DevTools HAR file and get a local performance, cache, host, asset, status, and security-header report.

Paste sitemap XML and audit URL count, HTTP links, duplicates, trailing-slash conflicts, query parameters, lastmod freshness, and extensions.

Build block__element--modifier the right way, normalized to kebab-case, with HTML and SCSS nesting examples, browser-only

Drag two handles, read the cubic-bezier() — five built-in presets, motion preview, solve y for any progress, browser-only

Truncate text after N lines with a trailing ellipsis, copy the CSS and the Tailwind class, with live preview, browser-only

CSS @media query + responsive breakpoint generator — Tailwind / Bootstrap / Material presets, mobile-first vs desktop-first, dark mode, hover, reduced-motion, aspect-ratio.

Score any CSS selector as an (a, b, c) triple, compare which rule wins the cascade, and see exactly which digit decided it — browser-only

Paste CSS declarations, get a React inline style object — kebab keys camelCased, vendor prefixes handled, optional bare numbers, browser-only

Paste a curl command, get JS fetch / Python requests / Node axios / PHP cURL / Go net/http — parsed locally, instant

Hide your email from scraper bots — HTML entities, [at]/[dot] text, ROT13+JS link — browser-only, one-click copy

Paste lang|url pairs, get hreflang link tags, HTTP Link header and sitemap XML with x-default and code validation, browser-only

Build an HTML table visually — rows/columns, header cells, alignment, borders, zebra stripes, paste CSV/TSV — copy clean markup, browser-only

Paste HTML, get React-ready JSX — class becomes className, inline styles become objects, tags self-close. Browser-only.

Parse, edit, and generate Google Fonts CSS2 links, HTML preconnect tags, @import CSS, variables, and Tailwind font stacks.

Build valid schema.org JSON-LD for Article, Product, FAQ, LocalBusiness, Event and more, copy the script tag, drop it in your head

Build a mailto link with recipients, cc, bcc, subject and a multi-line body. Correct URL encoding, copy as plain URL or HTML anchor, all in your browser.

Turn Markdown into React-ready JSX — one paste from README to a real component, with class becoming className and code blocks intact. Browser-only.

Inline any SVG as a data URI — URL-encoded (smaller) or base64 — with ready-to-paste CSS, HTML and bare-URI output, side-by-side size diff, 100% in-browser.

Paste SVG, get a React component — attributes camelCase, style becomes an object, wrap with {...props} passthrough. Browser-only.

Build twitter:card meta tags for X with a live card preview, Open Graph fallback and one-click copy, all in your browser

Break any URL into protocol, host, port, path, query and hash, with a decoded parameter table, all in your browser

Generate Apache .htaccess — HTTPS redirect, www toggle, gzip, cache headers, hotlink protection.

Generate robots.txt with templates for common crawlers (Google, Bing, AI scrapers).

Cron expression explainer — paste any cron, get plain English/Chinese + next 20 runs + visual time grid.

Visual crontab builder + human-readable explanation + next run preview.

Linux permission (chmod) calculator — convert between octal (755), symbolic (rwxr-xr-x), and ls -l forms, with safety warnings.

Unix timestamp ⇄ human date — seconds / milliseconds / ISO 8601 — UTC and local — browser-only

Clean noisy logs by removing timestamps, ANSI colors, blank lines, long lines, or non-error entries in your browser.

Paste logs and group repeated errors, warnings, stack traces, HTTP statuses, endpoint patterns, and time ranges into a local incident report.

Scan .env files, config snippets, and CI logs locally for likely API keys, tokens, private keys, JWTs, and database URLs.

Inspect package-lock.json, pnpm-lock.yaml, or yarn.lock for duplicate versions, risky sources, prereleases, and missing integrity.

Audit OpenAPI JSON or YAML for endpoint coverage, missing operation IDs, security gaps, and weak response documentation.

Check robots.txt for user-agent groups, allow and disallow rules, sitemap declarations, crawl-delay, and unsupported directives.

Audit raw response headers for HSTS, CSP, cookie flags, MIME sniffing, clickjacking, referrer, and permissions policy gaps.

Inspect Content-Security-Policy directives for unsafe sources, missing fallbacks, framing gaps, object-src, base-uri, and reporting coverage.

Upload a Chrome DevTools HAR file and get a local performance, cache, host, asset, status, and security-header report.

Paste sitemap XML and audit URL count, HTTP links, duplicates, trailing-slash conflicts, query parameters, lastmod freshness, and extensions.

Tick the directives, set the lifetime, copy a correct Cache-Control header plus Nginx and Apache lines

Build a spec-perfect commit line from a type, scope, and one-line summary, with live validation and footers

Pick an origin, methods and headers, get Access-Control-* response headers as a raw list, Nginx, Apache or Express code

Build a Content-Security-Policy from directive toggles, get the header line, meta tag and Nginx snippet, with live unsafe-inline warnings, browser-only

Visual .editorconfig builder — indent, charset, line endings, trailing whitespace, per-glob overrides — browser-only

Strip illegal characters and make any string a safe cross-platform filename, in your browser

Pick your stack — Node, Python, Go, Docker, macOS, VS Code — and get a deduped, sectioned .gitignore. Browser-only.

Test which paths a glob matches — supports * ** ? [a-z] {js,ts} and ! — see the equivalent regex — browser-only

Generate Apache/Nginx .htpasswd lines — bcrypt, apr1 (MD5), SHA-1 — multi-user, copy, download — 100% browser-only

Paste raw HTTP headers, get a clean table with per-header meaning, duplicate and security badges, browser-only

Type an IPv4 CIDR and get network, broadcast, host range, mask, wildcard, class and subnet splits — browser-only.

Pick MIT, Apache, BSD, GPL and 4 more, fill in your name and year, get a ready-to-save LICENSE file. Browser-only.

Tell which semantic version is newer, sort a whole list, and check ^ ~ >= ranges, all in the browser

Bump a version the npm way and see major, minor, patch and every pre-release result at once, all in the browser

Quote any string for bash safely: single-quote wrap, double-quote escape, backslash mode, and reverse, all in your browser

Parse any User-Agent string into browser, engine, OS, device type and bot flag — paste a log line or read your own — browser-only

Generate eval cases, pass criteria, and edge cases from an AI feature, risks, and user path.

Validate your App Store title, subtitle and 100-char keyword field before launch — live character counts, keyword overlap detection, asset checklist

Code 128 / EAN-13 / UPC-A / Code 39 — generate scannable 1D barcodes, export SVG or PNG, fully offline.

Turn big integers and UTF-8 text into compact 0-9A-Za-z strings, the way short-URL services pack an ID into 6 characters, all in your browser

Find duplicates and keep one clean copy of base64 blocks from pasted text or uploaded local files.

Extract, dedupe, and export base64 blocks from pasted text or uploaded local files.

Convert base64 blocks from pasted text or uploaded local files.

Validate and explain issues in base64 blocks from pasted text or uploaded local files.

Normalize, sort, and prepare base64 blocks from pasted text or uploaded local files.

Base64 ⇄ hexadecimal at the byte level, no text encoding in between — standard or URL-safe, your separator and case, runs in your browser

Encode and decode URL-safe Base64 strings for JWT headers, payloads, tokens, and URL parameters without padding surprises.

Border radius generator — independent 8-corner control + blob shape randomizer, live preview, copy CSS or SVG path.

Paste CSS variables or JSON tokens, select fg/bg pairs, and flag every WCAG AA/AAA failure across your design system at once.

Pad delimited rows into an even monospace grid, like column -t, with correct CJK width — browser-only

Paste Tailwind colors, CSS theme tokens, or JSON palettes and audit every foreground/background pair for WCAG AA and AAA contrast.

Find duplicates and keep one clean copy of credit card numbers from pasted text or uploaded local files.

Extract, dedupe, and export credit card numbers from pasted text or uploaded local files.

Convert credit card numbers from pasted text or uploaded local files.

Validate and explain issues in credit card numbers from pasted text or uploaded local files.

Normalize, sort, and prepare credit card numbers from pasted text or uploaded local files.

Cron cheat sheet — 80+ entries covering syntax, time expressions, special strings, environment variables, crontab management, and common pitfalls.

Design buttons that look pressable — 3D raised, neumorphic, glass — with a live preview you can hover & press, plus full :hover/:active CSS export

Convert any color between HEX, RGB, HSL, OKLCH, CSS variable, and Tailwind — with live preview.

Dial in blur, brightness, contrast, grayscale, sepia, hue-rotate, saturate, invert, opacity + drop-shadow with live preview — copy the filter string

Generate production-ready flexbox CSS from visual controls — pick a layout preset, tweak properties, copy CSS, Tailwind, or React inline styles in one click.

Visual CSS Flexbox sandbox — tweak container and item properties live, see the layout update instantly, copy ready-to-use CSS.

Visually build @keyframes — edit keyframes, set transform/opacity/color, live-preview, and copy production-ready CSS — browser-only

Design custom scrollbars visually — exports WebKit + Firefox-standard CSS, live preview, one-click copy — browser-only

Pure-CSS triangles via the border trick — 8 directions, live preview, copy both border + clip-path CSS — browser-only

Find duplicates and keep one clean copy of css variables from pasted text or uploaded local files.

Extract, dedupe, and export css variables from pasted text or uploaded local files.

Convert css variables from pasted text or uploaded local files.

Validate and explain issues in css variables from pasted text or uploaded local files.

Normalize, sort, and prepare css variables from pasted text or uploaded local files.

Paste CSV, get a compile-ready LaTeX tabular with booktabs, l/c/r alignment, a table environment and safe escaping, all in your browser

Turn a spreadsheet export into a clean YAML array of objects — RFC 4180 quoting, optional type inference, browser-only

bps / Kbps / Mbps / Gbps ⇄ B/s, KB/s, MB/s — bit-rate vs byte-rate, 8x apart — browser-only

Find duplicates and keep one clean copy of domain names from pasted text or uploaded local files.

Extract, dedupe, and export domain names from pasted text or uploaded local files.

Convert domain names from pasted text or uploaded local files.

Validate and explain issues in domain names from pasted text or uploaded local files.

Normalize, sort, and prepare domain names from pasted text or uploaded local files.

Find duplicates and keep one clean copy of email addresses from pasted text or uploaded local files.

Extract, dedupe, and export email addresses from pasted text or uploaded local files.

Convert email addresses from pasted text or uploaded local files.

Validate and explain issues in email addresses from pasted text or uploaded local files.

Normalize, sort, and prepare email addresses from pasted text or uploaded local files.

Fill in your details, pick a template, get table-based inline-style HTML that pastes cleanly into Gmail and Outlook — 100% browser-only

Convert .env environment variables to JSON and back, with quote escaping, export prefix, and optional type inference, all in your browser

Find duplicates and keep one clean copy of environment variables from pasted text or uploaded local files.

Extract, dedupe, and export environment variables from pasted text or uploaded local files.

Convert environment variables from pasted text or uploaded local files.

Validate and explain issues in environment variables from pasted text or uploaded local files.

Normalize, sort, and prepare environment variables from pasted text or uploaded local files.

Turn column letters into numbers and back: A is 1, Z is 26, AA is 27, batch convert, paste A1 refs, copy in one click, all in your browser

Batch find-and-replace on big text — regex, $1 capture groups, whole-word, case toggle, multiple chained rules — runs entirely in your browser

Flexbox playground — toggle every container and item property on a real flex box and copy the exact CSS. direction, justify, align, gap, order, grow/shrink/basis, align-self. 100% client-side.

GitHub README badge generator — shields.io-style badges, 50+ presets (build/version/license/coverage/etc), custom labels, copy as Markdown/HTML/AsciiDoc/RST.

GitLab CI/CD cheat sheet — 80+ entries covering pipeline structure, job config, rules, variables, artifacts, runners, templates, security, and the GitLab API.

Paste any hash string and instantly identify MD5, SHA-256, bcrypt, Argon2, and 30+ other formats

HMAC-SHA1/256/384/512 — message + secret key, output in hex and base64, key read as UTF-8/hex/base64 — 100% in-browser

Paste an HTML <table>, get clean JSON, array of objects or 2D array, type inference, browser-only

Paste an HTML table, get a clean GitHub-flavoured Markdown table with the |---| separator row, tags stripped, entities decoded and pipes escaped, all in your browser

Find duplicates and keep one clean copy of http headers from pasted text or uploaded local files.

Extract, dedupe, and export http headers from pasted text or uploaded local files.

Convert http headers from pasted text or uploaded local files.

Validate and explain issues in http headers from pasted text or uploaded local files.

Normalize, sort, and prepare http headers from pasted text or uploaded local files.

Turn INI / .cfg / .conf into JSON and back, with section nesting, comment stripping and optional type inference, all in your browser

Find duplicates and keep one clean copy of ipv4 addresses from pasted text or uploaded local files.

Extract, dedupe, and export ipv4 addresses from pasted text or uploaded local files.

Convert ipv4 addresses from pasted text or uploaded local files.

Validate and explain issues in ipv4 addresses from pasted text or uploaded local files.

Normalize, sort, and prepare ipv4 addresses from pasted text or uploaded local files.

Find duplicates and keep one clean copy of ipv6 addresses from pasted text or uploaded local files.

Extract, dedupe, and export ipv6 addresses from pasted text or uploaded local files.

Convert ipv6 addresses from pasted text or uploaded local files.

Validate and explain issues in ipv6 addresses from pasted text or uploaded local files.

Normalize, sort, and prepare ipv6 addresses from pasted text or uploaded local files.

Paste a JS object literal or JSON5, get strict JSON: quote bare keys, swap single quotes, strip comments and trailing commas, runs in your browser

Turn a JSON array (or object) into clean CSV — flattens nested keys, escapes per RFC 4180, custom delimiter, UTF-8 BOM for Excel — browser-only

Paste a JSON array of objects, get a clean GitHub-flavored Markdown table. Key union, pipe escaping, alignment, all in your browser.

Paste a JSON document, get a typed mongoose.Schema with the model export, nested sub-schemas, date detection, browser-only

JSON array to NDJSON and back, one compact JSON value per line, with bad-line numbers and pick-your-indent, all in your browser

Paste JSON, get Pydantic BaseModel classes with type hints, nested sub-models, List[T], Optional inference, v1 / v2 and aliases.

Paste JSON, get a Ruby Hash literal or Struct.new classes; symbol or string keys, null maps to nil, nested objects, zero upload.

Paste JSON, get Scala case classes. Nested objects become child classes, arrays become List, null becomes Option, all in your browser.

Turn a JSON array into ready-to-run INSERT statements, MySQL / PostgreSQL / SQLite dialects, browser-only

Paste JSON, get clean TOML with proper tables and arrays of tables, all in your browser

Turn a JSON array into tab-separated values you can paste straight into Excel or Google Sheets, with header toggle and safe escaping, all in your browser

Convert JSON to clean, indented XML — @attr/#text conventions, custom root, escaped output. Browser-only.

Convert JSON to clean YAML — block scalars for multiline strings, optional key sorting, 2/4-space indent, line-numbered errors — browser-only

Turn newline-delimited JSON into a JSON array and back, with bad-line numbers and pick-your-indent — browser only

JSONPath / JMESPath query tester — paste JSON, write a path, see matched values + matched paths highlighted live.

Find duplicates and keep one clean copy of jwt tokens from pasted text or uploaded local files.

Extract, dedupe, and export jwt tokens from pasted text or uploaded local files.

Convert jwt tokens from pasted text or uploaded local files.

Validate and explain issues in jwt tokens from pasted text or uploaded local files.

Normalize, sort, and prepare jwt tokens from pasted text or uploaded local files.

Compare two lists line by line: only in A, only in B, in both, and merged — all in your browser

Turn a column of lines into a JSON array, with type inference, dedupe and pretty print, and split it back to lines, all in your browser

Estimate daily and monthly LLM spend from tokens, request volume, and editable model prices.

Logrotate cheat sheet — directives, CLI flags, postrotate scripts, pitfalls, and copy-ready config templates for nginx, rsyslog, and app logs.

Grafana Loki cheat sheet — 80+ entries covering LogQL stream selectors, line filters, parsers, metric queries, aggregations, Promtail stages, Loki config, and HTTP API.

Find duplicates and keep one clean copy of mac addresses from pasted text or uploaded local files.

Extract, dedupe, and export mac addresses from pasted text or uploaded local files.

Convert mac addresses from pasted text or uploaded local files.

Validate and explain issues in mac addresses from pasted text or uploaded local files.

Normalize, sort, and prepare mac addresses from pasted text or uploaded local files.

Turn GitHub Markdown into clean AsciiDoc, headings, source blocks, url[text] links and image:: macros, all in your browser

Paste Markdown, get forum BBCode in real time. Bold, links, lists, code blocks and quotes mapped to [b] [url=] [list] [code] [quote], browser only

Paste Markdown, get Confluence wiki markup — h1. headings, {code} panels, ||tables|| and {quote} blocks, all in your browser

Paste GitHub-flavored Markdown, get Jira wiki markup back — headings, bold, code blocks, tables, links, all in your browser

Convert Markdown to Emacs Org-mode with star headlines, /italic/ slashes, ~code~ verbatim and [[url][text]] links, all in the browser

Convert Markdown to RST for Sphinx and Python docs, with matched heading underlines, double-backtick code and `text <url>`_ links, in the browser

Paste standard Markdown, get Slack mrkdwn back: single-star bold, underscore italic, single-tilde strike, angle-bracket links, all in your browser

Paste GitHub-flavored Markdown, get Textile markup back for Redmine and wikis, with headings, bold, code blocks, links and images converted in your browser

Generate URL-safe NanoIDs with a custom alphabet, adjustable length, and a live collision-probability readout — entirely in your browser.

Netlify _redirects and netlify.toml cheatsheet for rewrites, proxies, SPA fallbacks, splats, status codes, and country/language rules.

Generate nginx.conf and Docker CMD for container log routing — access_log /dev/stdout, error_log /dev/stderr, daemon off.

Pull every number out of any text: integers, decimals, negatives, 1,234 commas, percents and 6.02e23, with instant sum and average

Generate a list of numbers from start to end by step or count, with zero-padding, prefix, suffix and any separator, all in your browser

OAuth 2.0 scope reference — 60+ scopes across Google, GitHub, Microsoft, Slack, Spotify, Discord and more, with access level, use cases and risk rating.

See your og:title, og:image and twitter:card exactly as Google, X, Facebook, LinkedIn, Slack and Discord will render them — before you ship.

package.json field reference — 55+ fields explained with real examples, bilingual, searchable.

Check password strength — entropy, time-to-crack, breach pattern check (offline).

Dense, searchable pnpm workspace reference — 60+ commands covering filter syntax, workspace protocols, recursive scripts, and monorepo pitfalls.

Prometheus cheat sheet — 90+ entries covering PromQL selectors, aggregations, functions, alerting rules, recording rules, HTTP API, and relabeling.

Java/Spring .properties to JSON and back, with dotted-key nesting, line continuations and full escape handling, all in your browser

Unicode ⇄ Punycode for internationalized domains — münchen.de ⇄ xn--mnchen-3ya.de — per-label, email-aware, browser-only

Quoted-Printable encode and decode by UTF-8 bytes, the way email MIME does it, with =XX escapes, trailing-space handling and 76-column soft wraps, all in your browser

RabbitMQ cheat sheet — 90+ commands and patterns for queues, exchanges, clustering, and common pitfalls.

Find duplicates and keep one clean copy of semantic versions from pasted text or uploaded local files.

Extract, dedupe, and export semantic versions from pasted text or uploaded local files.

Convert semantic versions from pasted text or uploaded local files.

Validate and explain issues in semantic versions from pasted text or uploaded local files.

Normalize, sort, and prepare semantic versions from pasted text or uploaded local files.

SSH config cheatsheet — 50+ directives for ~/.ssh/config with copy-ready examples and common pitfalls.

Paste once — see escaped strings for JSON, Python, Go, C#, Rust, Java, C, Ruby, PHP, Swift, Kotlin & JS side by side

Levenshtein edit distance, Dice, Jaro-Winkler and LCS side by side, with a 0-100% match score, all in your browser

SVG optimizer — strip comments/metadata/empty attributes, round path decimals, collapse useless groups, minify in browser. No upload.

Terraform cheat sheet — 90+ commands for init, plan, apply, state, workspaces, import, and debug with real examples.

Paste TOML, get clean JSON instantly — full TOML 1.0 support, error messages with line numbers, 100% in-browser

Tab-separated data to JSON, header detection, type inference, quoted tab/newline fields, browser-only

Pick a base size + ratio (Major Third, Perfect Fourth, Golden…) and get a full modular type scale with px + rem, live preview, and CSS / Tailwind / SCSS export — browser-only

TypeScript tsconfig.json cheat sheet — 55+ options with defaults, examples, and gotchas.

Inspect any text character-by-character: code points, UTF-8/UTF-16 bytes, HTML entities, JS escapes, names, and hidden zero-width / confusable glyphs.

Inspect any character — code point, UTF-8 bytes, UTF-16 encoding, Unicode category, script, and block — instant, browser-only

Paste text → get a per-code-point table: U+XXXX, UTF-8 bytes, UTF-16, HTML entity, JS escape, character name.