Encoding & Crypto for Developer

93 encoding & crypto tools hand-picked for Developer.

AES Text Encryptor

Encrypt & decrypt text with a password — AES-256-GCM + PBKDF2 via WebCrypto — 100% in your browser, nothing uploaded
Affine Cipher Encoder & Decoder

Encrypt and decrypt the ax+b affine cipher with live modular-inverse check, browser-only
Atbash Cipher

Mirror the alphabet, A↔Z B↔Y, no key, self-reciprocal so the same button encodes and decodes, browser-only
Bacon Cipher Encoder & Decoder

Turn text into five-letter A/B groups, or read a Baconian message back — 24 and 26 letter alphabets, custom symbols, browser only
Base32 / Base58 Encoder & Decoder

Base32 + Base58 encoder/decoder — RFC 4648 base32 (Crockford variant too), Bitcoin base58, Solana base58, hex/text/file input.
Base62 Encoder & Decoder

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
Base64 Block Deduplicator

Find duplicates and keep one clean copy of base64 blocks from pasted text or uploaded local files.
Base64 Block Extractor

Extract, dedupe, and export base64 blocks from pasted text or uploaded local files.
Base64 Block List Converter

Convert base64 blocks from pasted text or uploaded local files.
Base64 Block List Validator

Validate and explain issues in base64 blocks from pasted text or uploaded local files.
Base64 Block Normalizer

Normalize, sort, and prepare base64 blocks from pasted text or uploaded local files.
Base64 Encoder & Decoder

Encode or decode Base64 — text, files, and Data URLs. Runs entirely in your browser.
Base64 Image Converter

Image ⇄ Base64 — drag-drop PNG/JPG/WebP/SVG, get data URI for CSS / HTML / Markdown.
Base64 Image Data URI Converter

Convert images to data URIs (base64 or URL-encoded), inspect any data URI, preview and download. 100% in-browser.
Base64 to File Converter

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

Base64 ⇄ hexadecimal at the byte level, no text encoding in between — standard or URL-safe, your separator and case, runs in your browser
Base64URL Encoder Decoder for JWT-Safe Strings

Encode and decode URL-safe Base64 strings for JWT headers, payloads, tokens, and URL parameters without padding surprises.
Base85 / Ascii85 Encoder & Decoder

Encode text to Ascii85 or Z85 and decode it back, UTF-8 safe, with z-compression and <~ ~> handling, all in your browser
Basic Auth Header Generator

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

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

C = (key − text) mod 26, reciprocal — one keyword both encrypts and decrypts — browser-only
JWT Decoder and Claims Inspector

Decode JWT headers and payloads locally, inspect registered claims, timing, audience and risk signals.
Caesar Cipher Encoder & Decoder

Encrypt, decrypt and brute-force a Caesar shift cipher — all 25 shifts at once, ROT13 shortcut, browser-only
Columnar Transposition Cipher

Keyword sets the column order, the grid does the scrambling — encrypt, decrypt, regular or irregular padding, all in your browser
CRC32 Checksum Calculator

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

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

Extract, dedupe, and export credit card numbers from pasted text or uploaded local files.
Credit Card Number List Converter

Convert credit card numbers from pasted text or uploaded local files.
Credit Card Number List Validator

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

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

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

Cryptographically secure word-based passphrases — pick word count, separator, casing; live entropy; 100% in-browser, never in the URL.
Duplicate File Finder

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

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

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

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

Compute SHA-1, SHA-256, SHA-384, or SHA-512 hashes for uploaded files entirely in the browser.
File to Base64 Converter

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

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

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

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

Encode/decode HTML entities — & < > " ' and all numeric refs — browser-only
HTML Entity Encoder / Decoder

Encode & decode all HTML5 entities — named, decimal, hex — XSS prevention and safe markup, 100% client-side
.htpasswd Generator

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

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

Escape and unescape strings for JSON, regex literals, and template literals — browser-only, instant output
JSON String Escape and Unescape Tool for Developers

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.
JWT Decoder

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

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

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

Extract, dedupe, and export jwt tokens from pasted text or uploaded local files.
JWT Token List Converter

Convert jwt tokens from pasted text or uploaded local files.
JWT Token List Validator

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

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

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

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

Extract, dedupe, and export mac addresses from pasted text or uploaded local files.
MAC Address List Converter

Convert mac addresses from pasted text or uploaded local files.
MAC Address List Validator

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

Normalize, sort, and prepare mac addresses from pasted text or uploaded local files.
MD5 / SHA Hash Generator

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

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

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

Generate strong, cryptographically random passwords and passphrases — entirely in your browser.
Password Strength Checker

Check password strength — entropy, time-to-crack, breach pattern check (offline).
Playfair Cipher Encoder & Decoder

Encrypt and decrypt with a 5x5 keyword square, digraph pairs and a live grid, browser-only
Polybius Square Cipher Encoder & Decoder

Turn letters into 5x5 grid coordinates and back, with a keyword square, origin switch and a live grid, browser-only
Punycode / IDN Converter

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

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

Generate QR codes from text, URL, WiFi or vCard — customize color and size, download as PNG or SVG.
Quoted-Printable Encoder / Decoder

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
Rail Fence Cipher Encoder & Decoder

Encrypt, decrypt and brute-force a rail fence zigzag cipher, with a live grid, rail count plus offset, browser-only
ROT13 Encoder & Decoder

ROT13 / ROT47 / Caesar cipher — encode and decode in your browser, instant.
ROT47 Encoder & Decoder

Rotate all visible ASCII by 47. Digits and symbols change too, fully self-inverse, runs in your browser.
Scytale Cipher Encoder & Decoder

Encrypt and decrypt the ancient Spartan scytale rod cipher, with a live rod grid and an adjustable diameter, browser-only
String Escape Converter

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

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

Knock cipher on a 5×5 grid, C and K share a cell, row taps then column taps, decode back to text, all in your browser
Text to Binary Converter

Text to binary (and back) — UTF-8 aware, 8/16/32 bit grouping, emoji safe.
Text to Hex Converter

Text ⇄ hexadecimal by UTF-8 bytes — Chinese and emoji safe, picks your separator and case, decodes messy pasted hex — runs in your browser
Unicode Code Point Explorer

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

Text ⇄ Unicode escapes — \uXXXX, \u{1F600}, 😀, CSS \1F600 — emoji + CJK done right, browser-only
Unicode Inspector and Normalizer

Inspect code points, names, categories, UTF-8 bytes and normalize text to NFC, NFD, NFKC or NFKD entirely in your browser.
URL Encoder Decoder with Query Parameter Table

Encode, decode, inspect query parameters, process bulk URL lists, and copy clean outputs entirely in your browser.
URL Encoder / Decoder

Encode and decode URL-unsafe characters — query strings, path segments, full URLs — instant, browser-only
URL Query String Parser & Builder

Paste a URL, see every parameter decoded in a table; edit the rows and get a clean, correctly-encoded query string back — %20 or +, sorted or not, in your browser
UUID Deduplicator

Find duplicates and keep one clean copy of uuids from pasted text or uploaded local files.
UUID Extractor

Extract, dedupe, and export uuids from pasted text or uploaded local files.
UUID List Converter

Convert uuids from pasted text or uploaded local files.
UUID List Validator

Validate and explain issues in uuids from pasted text or uploaded local files.
UUID Normalizer

Normalize, sort, and prepare uuids from pasted text or uploaded local files.
Vigenère Cipher Encoder / Decoder

Encrypt and decrypt with a keyword, polyalphabetic shift, case kept, non-letters passed through, browser-only
ZIP Manifest Inspector

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

AES Text Encryptor

Affine Cipher Encoder & Decoder

Atbash Cipher

Bacon Cipher Encoder & Decoder

Base32 / Base58 Encoder & Decoder

Base62 Encoder & Decoder

Base64 Block Deduplicator

Base64 Block Extractor

Base64 Block List Converter

Base64 Block List Validator

Base64 Block Normalizer

Base64 Encoder & Decoder

Base64 Image Converter

Base64 Image Data URI Converter

Base64 to File Converter

Base64 to Hex Converter

Base64URL Encoder Decoder for JWT-Safe Strings

Base85 / Ascii85 Encoder & Decoder

Basic Auth Header Generator

Bcrypt Generator

Beaufort Cipher

JWT Decoder and Claims Inspector

Caesar Cipher Encoder & Decoder

Columnar Transposition Cipher

CRC32 Checksum Calculator

Credit Card Number Deduplicator

Credit Card Number Extractor

Credit Card Number List Converter

Credit Card Number List Validator

Credit Card Number Normalizer

CSP Policy Auditor

Diceware Passphrase Generator

Duplicate File Finder

Email Obfuscator

ENV Secret Scanner

File Checksum Compare

File Hash Calculator

File to Base64 Converter

Hash Type Detector

Hex Dump Viewer

HMAC Generator

HTML Entities Encoder

HTML Entity Encoder / Decoder

.htpasswd Generator

HTTP Security Header Auditor

JavaScript String Escaper

JSON String Escape and Unescape Tool for Developers

JWT Decoder

JWT Encoder

JWT Token Deduplicator

JWT Token Extractor

JWT Token List Converter

JWT Token List Validator

JWT Token Normalizer

Local File Workbench

MAC Address Deduplicator

MAC Address Extractor

MAC Address List Converter

MAC Address List Validator

MAC Address Normalizer

MD5 / SHA Hash Generator

OAuth Scope Cheatsheet

Package Lock Dependency Auditor

Password Generator

Password Strength Checker

Playfair Cipher Encoder & Decoder

Polybius Square Cipher Encoder & Decoder

Punycode / IDN Converter

Batch QR Code Decoder

QR Code Generator

Quoted-Printable Encoder / Decoder

Rail Fence Cipher Encoder & Decoder

ROT13 Encoder & Decoder

ROT47 Encoder & Decoder

Scytale Cipher Encoder & Decoder

String Escape Converter

String Escape / Unescape

Tap Code Translator

Text to Binary Converter

Text to Hex Converter