What is Base91 Tool?
basE91 is an advanced method for encoding binary data as ASCII text. It is similar to Base64 but is significantly more efficient. The overhead produced by basE91 depends on the input data but amounts to at most 23% (compared to 33% for Base64 and 25% for Ascii85). It uses 91 printable ASCII characters. This makes it one of the most space-efficient binary-to-text encoding schemes available, ideal for transmitting large amounts of data over text-based protocols.
Input Formats
- Plain text
- Base91 strings
- Binary data
Output Results
- Base91 string
- Decoded text
- Copy-ready result
Key Features
Who is this for?
Bandwidth Optimization
Transmitting large binary payloads over JSON or XML where size matters.
Email Attachments
Sending files via email with less overhead than standard Base64 encoding.
Database Storage
Storing binary blobs in text fields with minimal wasted space.
How to Use
Paste your text or Base91 string.
Select 'Encode' to convert to Base91.
Select 'Decode' to convert back.
Copy the result.
Examples
Input
Hello WorldOutput
>OwJh>Io0TvCommon Errors
- Using characters outside the Base91 alphabet
- Expecting standard padding (Base91 doesn't use it)
- Compatibility issues (less common than Base64)
Code Examples
C
// basE91 C library usage
struct basE91 b91;
basE91_init(&b91);
basE91_encode(&b91, input, len, output);