What is the difference between Adobe ASCII85 and RFC 1924?

Adobe ASCII85 uses the character range ! to u (33–117) plus z as a shorthand for four zero bytes, and wraps the encoded output in delimiters. RFC 1924 uses a different 85-character alphabet (0–9, A–Z, a–z, and a set of symbols) and has no delimiters. Neither uses padding characters.

Is Base85 more efficient than Base64?

Yes. Base85 encodes every 4 bytes as exactly 5 ASCII characters, giving ~25% size overhead. Base64 encodes every 3 bytes as 4 characters, giving ~33% overhead. For large binary payloads, Base85 is meaningfully smaller.

Can I encode arbitrary binary data here?

This tool works on UTF-8 text input. It encodes the UTF-8 byte sequence of the text you type. For raw binary files (images, executables) you would need a file-upload workflow; this tool is text-in / text-out.

What does the z shorthand mean in Adobe ASCII85?

In the Adobe variant, a group of four zero bytes (0x00000000) is represented by the single character z instead of the five-character sequence !!!!!. This makes zero-heavy data significantly shorter.

Is this conversion done on the server?

No. All encoding and decoding runs entirely in your browser using JavaScript. Nothing you type is sent to any server.

Base85 Encoder

Name: Base85 Encoder
Availability: InStock
Author: Nham Vu

Encode or decode text using Base85 (ASCII85) encoding — choose between Adobe ASCII85 and RFC 1924 variants.

Variant:

Input 0 bytes

Output 0 chars

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Summary

Encode or decode text using Base85 (ASCII85) encoding — choose between Adobe ASCII85 and RFC 1924 variants.

How it works

Enter text (or Base85 string) in the input panel.
Select the variant: Adobe ASCII85 or RFC 1924.
Click Encode or Decode to convert.
The result appears in the output panel.
Use the Copy button to copy the output to your clipboard.

Use cases

Encode binary data for embedding in PostScript or PDF documents.
Decode ASCII85-encoded payloads found in PDFs or network captures.
Work with RFC 1924 Base85 as used by Git bundle signatures.
Compare encoding efficiency versus Base64 for a given input.
Convert binary blobs to printable text for safe transport.
Validate that a Base85 string decodes to an expected plaintext.
Learn the difference between Adobe and RFC 1924 alphabets.
Prototype encoding logic before integrating into an application.

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu