Base64
Encode and decode, with a URL-safe variant.
About Base64
Base64 encodes and decodes text, including a URL-safe variant that swaps + and / for - and _ and drops the padding. The encoding here is Unicode-safe: the browser’s built-in btoa throws on anything above Latin-1, so text is passed through TextEncoder first, meaning Arabic and emoji work correctly.
How to use it
- Choose encode or decode.
- Paste your text.
- Copy the result. Switching mode carries the output across so you can round-trip.
Questions
Is Base64 encryption?
No, absolutely not. It is an encoding, trivially reversible by anyone. Never use it to hide a password or a secret.
When do I need the URL-safe variant?
When the value goes into a URL path or query string, where + and / have special meaning. JWTs use this variant.
Why does encoding make my text bigger?
Base64 represents three bytes as four characters, so output is about 33% larger. That is the cost of making binary data safe to put in text.
Base64 is free and runs entirely in your browser. No account, no upload, no watermark, no limit on use.