How is Base85 different from Base64, and when is it worth using?

Base64 turns 3 bytes into 4 characters, a 33% size increase. Base85 turns 4 bytes into 5 characters, only about 25% overhead, because 85^5 (4.4 billion) is just big enough to hold every 32-bit value (4.29 billion). So encoding the same 1 KB blob, Base64 gives ~1366 chars and Base85 gives ~1280. That margin is why Adobe PDF/PostScript streams and git's binary patch format use Ascii85 instead of Base64. For URLs and email, Base64 is still the safer default since Base85's punctuation can break in those contexts.

What is the difference between Ascii85 and Z85?

Both pack 4 bytes into 5 characters, but they use different alphabets. Adobe Ascii85 uses the 85 characters from `!` (33) to `u` (117), which includes characters like backslash and quotes that are awkward inside source strings. ZeroMQ's Z85 (RFC 32/Z85) was designed so the output is safe to paste directly into source code, JSON and shell, so it avoids backslash, backtick and quote. Z85's spec officially only covers data whose length is a multiple of 4 bytes; this tool pads shorter input the Ascii85 way so arbitrary text still round-trips.

What do the ` ` markers around Ascii85 output mean?

They are Adobe's start and end delimiters for an Ascii85 stream. PDF and PostScript wrap encoded data as ` ` so a parser knows exactly where the encoded block begins and ends. They are optional: the raw five-character groups decode fine without them. This tool can add them on encode (the wrap checkbox) and always recognizes and strips them on decode, so you can paste a PDF stream fragment straight in. The decoder is lenient and also tolerates whitespace between the markers.

What does the `z` shortcut do in Ascii85?

When a full four-byte group is all zeros (0x00000000), Ascii85 would normally produce five `!` characters. Instead the spec lets you write a single `z` to stand for that whole group, which shrinks long runs of zero bytes dramatically, common in sparse binary data. For example four zero bytes encode to just `z`. Note `z` is only valid for a complete zero group at a group boundary; a `z` appearing mid-group is an error, and this tool reports it rather than guessing.

How does it handle Chinese characters and emoji?

Text is converted to UTF-8 bytes with the browser's TextEncoder before any Base85 math happens, and decoding runs TextDecoder('utf-8') on the recovered bytes. So `你好` becomes its 6 UTF-8 bytes, gets packed into Base85, and comes back as `你好` exactly. Emoji like `🚀` are 4-byte UTF-8 sequences and survive the same way. This avoids the classic bug where naive byte handling mangles anything above the ASCII range, and it means the tool is a real Unicode codec, not an ASCII-only one.

Recover a corrupted git binary patch fragment

A git diff --binary patch failed to apply and you suspect a line got truncated in transit. Git wraps binary deltas in a length-prefixed Base85, so paste a suspect block in Decode mode and the tool flags the exact character where the alphabet breaks, telling you which line lost bytes instead of guessing across the whole hunk.

Hand-build an Ascii85 stream for a PostScript test

You're debugging a PostScript interpreter and need a known stream block to feed it. Type your bytes, encode as Ascii85, tick the wrap checkbox, and copy the delimited output straight into your .ps file. The z-shortcut collapses any zero runs the way a real Adobe encoder would, so the interpreter sees genuine stream input.

Base85 / Ascii85 Encoder & Decoder: Ascii85 and Z85, UTF-8 Safe

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

Runs locally
Category Encoding & Crypto
Best for Checking small payloads, tokens, hashes, and encoded values quickly.

Variant

Wrap with <~ ~>

Input

Examples

Output

What this tool does

Free online Base85 tool that encodes and decodes both the Adobe Ascii85 variant and the ZeroMQ Z85 variant. Base85 packs every 4 bytes into 5 printable characters, so it carries roughly 25% less overhead than the 33% you pay with Base64, which is why PDF streams, PostScript and git binary diffs reach for it. Type or paste any text and it is read as UTF-8 bytes first (via TextEncoder), so Chinese, Japanese, Arabic and emoji all survive the round trip byte for byte. Ascii85 mode supports the classic "z" shorthand that collapses an all-zero four-byte group to one letter, plus optional `<~ ~>` delimiters that match Adobe output. Decoding is forgiving: it skips spaces, tabs and newlines, recognizes the `<~ ~>` markers automatically, and reports the exact offending character when the input is malformed. Everything runs client-side with one-click copy and a shareable URL. 100% in-browser, nothing is uploaded.

Tool details

Input: Text; The page exposes text boxes, numeric controls, file pickers, or structured inputs depending on the tool.
Output: Live result + Copy; The result area focuses on usable output, with copy, download, or preview actions when supported.
Privacy: Browser-side processing; The main tool logic does not call an external API, so inputs normally stay in the current tab.
Save / share: Shareable URL state; Key settings are encoded in the URL so another person can reopen the same setup.
Performance budget: Initial JS <= 9 KB; No WASM budget is declared, keeping the tool quick to open on mobile.
Best fit: Encoding & Crypto · Developer; Category and role tags drive related tools, internal links, and quick fit checks.

How to use

1. Input

Paste or drop your content into the tool panel.
2. Process

Click the button. All processing is local in your browser.
3. Copy / Download

Copy the result or download to disk in one click.

How Base85 / Ascii85 Encoder & Decoder fits into your work

Use it for quick browser-side encoding, decoding, hashing, token checks, and share-safe transformations.

Encoding jobs

Checking small payloads, tokens, hashes, and encoded values quickly.
Preparing values for APIs, URLs, docs, or support tickets.
Avoiding account-based tools when the input might be sensitive.

Encoding checks

Do not paste live secrets unless you are comfortable with local browser handling.
Confirm whether the operation is reversible before sharing the result.
For hashes, compare the exact algorithm and casing expected by the receiver.

Good next steps

These links move the current task into a more complete workflow.

Real-world use cases

Recover a corrupted git binary patch fragment
A git diff --binary patch failed to apply and you suspect a line got truncated in transit. Git wraps binary deltas in a length-prefixed Base85, so paste a suspect block in Decode mode and the tool flags the exact character where the alphabet breaks, telling you which line lost bytes instead of guessing across the whole hunk.
Hand-build an Ascii85 stream for a PostScript test
You're debugging a PostScript interpreter and need a known stream block to feed it. Type your bytes, encode as Ascii85, tick the wrap checkbox, and copy the delimited output straight into your .ps file. The z-shortcut collapses any zero runs the way a real Adobe encoder would, so the interpreter sees genuine stream input.

Common pitfalls

Decoding an Ascii85-delimited block while still in Z85 mode. The markers are an Ascii85 convention; switch the variant to Ascii85 first, or the bracket characters land outside the Z85 alphabet and error.
Assuming output length stays fixed when input isn't a multiple of 4 bytes. A 5-byte input still produces a partial trailing group, so don't compare lengths assuming clean 4-to-5 ratios.
Trusting a successful decode as proof of the right variant. An Ascii85 string can sometimes decode under Z85 to plausible-looking bytes; verify the round trip re-encodes to the original, not just that decoding ran.

Privacy

The whole pipeline runs as JavaScript in this tab: UTF-8 encoding, Base85 group packing, the z-shortcut, and decoding. Nothing you paste reaches a server and nothing is logged. One caveat: the share URL stores your input and variant in the query string so a link rebuilds the result, which also means it lands in the recipient's server logs. For secrets, copy the output instead of sharing the link.

FAQ

Tool combos

Folks in your role tend to reach for these alongside this tool.

Developer

Browse all tools for this role

Base85 / Ascii85 Encoder & Decoder: Ascii85 and Z85, UTF-8 Safe

What this tool does

Tool details

How to use

1. Input

2. Process

3. Copy / Download

How Base85 / Ascii85 Encoder & Decoder fits into your work

Encoding jobs

Encoding checks

Good next steps

Real-world use cases

Recover a corrupted git binary patch fragment

Hand-build an Ascii85 stream for a PostScript test

Common pitfalls

Privacy

FAQ

MD5 / SHA Hash Generator

Number Base Converter

Base64 Encoder & Decoder

Base32 / Base58 Encoder & Decoder

Text to Hex Converter

URL Encoder / Decoder

AES Text Encryptor

Affine Cipher Encoder & Decoder

Atbash Cipher

Bacon Cipher Encoder & Decoder

Base62 Encoder & Decoder

Base64 Block Deduplicator