logohsb.horse

Base64 Encoder and Decoder

Convert UTF-8 text to and from Standard Base64 or Base64url safely in your browser.

Choose Standard Base64 or Base64url explicitly so alphabet and padding differences are never guessed.

Input and output stay in this browser.

Base64 variant
Operation
Standard Base64
Uses the + and / alphabet and emits required padding with =.
Base64url
Uses the URL-safe - and _ alphabet and emits no padding.
Input
Result

How to use

  1. 1

    Choose a variant

    Select Standard Base64 or Base64url for the input or destination.

  2. 2

    Choose an operation and enter text

    Select encode or decode, then enter UTF-8 text or a Base64 string.

  3. 3

    Transform and copy

    Run the transformation, inspect the result, and copy it to your clipboard.

Variant and padding rules

Standard Base64 output includes required padding. Base64url output omits padding, while its decoder accepts correctly padded and unpadded input. ASCII whitespace is ignored during decoding, but the alphabet is never detected automatically.

FAQ

Why is there no = at the end of Base64url output?
This tool emits unpadded Base64url. Its decoder also accepts input with correctly placed padding.
Does the tool detect Standard Base64 and Base64url automatically?
No. Input using + or / in Base64url mode, or - or _ in Standard mode, is rejected instead of guessed.
Can it convert files or arbitrary binary data?
No. This tool handles UTF-8 text only and never reads or uploads a file.