Ascii85 / Base85 Encoder / Decoder

Encode bytes into Ascii85/Base85 text, or decode Base85 variants back into readable UTF-8 or hex bytes.

How Base85 works

Base85 turns four bytes into one 32-bit number, converts that number into five base-85 digits, then maps those digits to printable characters. It is encoding, not encryption.

Block: 4 bytes -> 5 chars Ascii85: ! through u Base85: RFC 1924 style Mode: Encode Variant: Ascii85

Variant and formats

Encoding variant

Encode textUTF-8 text becomes bytes first. Encode hex bytesUse exact bytes such as 41 42 43 44. Decode as textShow bytes as UTF-8 when readable. Decode as hexBest for arbitrary binary output.

Text input is encoded as UTF-8 bytes before Base85 packing.

Options

Use Adobe markers <~ ~>

Use z for four zero bytes

Use y for four spaces

Ignore whitespace while decoding

Wrap encoded output at 75 characters

Output stats

Input chars: 0 Input bytes: 0 Output chars: 0 Output bytes: 0 Size change: --

Ascii85 and Base85 are reversible encodings. They help bytes travel as text, but they do not hide secrets or protect private data.

Input text

Output Ascii85

Using This Tool: Guide & Notes Show guide

Ascii85 and Base85 are binary-to-text encodings that pack 4 bytes into 5 printable characters. They are more compact than Base64, but variant details matter.

How to use it

Choose Encode to turn text or hex bytes into Ascii85/Base85, or Decode to recover UTF-8 text or hex bytes.
Select the variant before processing. Ascii85 and RFC 1924/Git-style Base85 use different alphabets.
Use text input for ordinary messages, or hex input when you want to experiment with exact byte values.
Use Load example to compare known outputs such as Hello, world! and ABCD.

Options and settings

Ascii85 can add or accept Adobe markers such as <~ and ~>.
z shorthand represents four zero bytes in Ascii85 when enabled.
y shorthand represents four spaces in btoa-style Ascii85 when enabled.
Ignore whitespace helps decode wrapped or pasted Base85 text.
Wrap encoded output breaks long encoded strings into readable lines.

Notes

Ascii85 and Base85 are encoding, not encryption. Anyone with the right decoder can reverse them.
If decoding fails, check for the wrong variant, misplaced z/y shorthand, broken Adobe markers, or a one-character final group.

Ascii85 and Base85: Packing Binary Into Fewer Characters Than Base64

How 4 bytes become 5 printable characters, why Ascii85 is not encryption, and why Base85 still matters in files, programming tools, and binary-to-text encoding.

Read the article

Signal acquired

A note from the team

We build these tools because we love cryptography, encoding, and making difficult ideas easier to explore. If they've helped you, even a small coffee means the world to the project. Thank you!

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