Base91 Decoder

Summary

Paste a Base91-encoded string and instantly decode it back to the original text — no server needed.

How it works

1. Paste your Base91-encoded string into the input field.
2. Click the Decode button (or decoded output updates as you type).
3. The tool processes pairs of characters using the 91-character alphabet.
4. Each pair encodes 13 bits, yielding up to 1.625 bytes per character on average.
5. The decoded text appears in the output panel immediately.
6. Use the Copy button to copy the result to your clipboard.

Use cases

• Decode Base91 payloads found in source code or config files.
• Reverse Base91-encoded strings from scripts or shell one-liners.
• Verify that a Base91 encoded value matches expected plaintext.
• Inspect Base91 data during security research or reverse engineering.
• Decode Base91 snippets from network captures or log files.
• Test Base91 round-trips when building encoding utilities.
• Recover text from Base91-encoded clipboard content.
• Compare Base91 output size against Base64 or Base85 alternatives.

Frequently Asked Questions