Base91 Codec
Online Base91 encoder/decoder with high compression ratio.
About This Tool
A professional online Base91 codec tool using Joachim Henke's canonical implementation. Base91 uses an alphabet of 91 printable ASCII characters (excluding three characters from the 94 printable set: dash -, apostrophe ', and backslash \) to encode binary data. Compared to Base64 which has an overhead of 33%, Base91 limits the overhead to just 23%. This makes it a great choice for transferring or storing binary data in systems that only support text. Note: Base91 has multiple implementation variants (such as r-lyeh's XML-Friendly variant), this tool uses the most widely adopted canonical implementation. Our tool allows you to convert from text or Hexadecimal, with all encoding/decoding happening 100% locally in your browser for absolute data privacy.
Features
- ⚡ High Efficiency: Uses up to 10% less space compared to Base64
- 🔄 Bidirectional: Encode and decode flexibly using UTF-8 Text or Hex strings
- ⚡ Real-time: Instant millisecond response as soon as you type
- 📋 Easy Copy: Copy results to your clipboard with one click
- 🔒 Privacy First: 100% processed locally without contacting a server