Base64 Encode & Decode Online — Free, No Upload
Turn text into Base64 (or turn a Base64 string back into text) with full Unicode support and an optional URL-safe alphabet for tokens and query parameters.
- Leave the direction on auto and the tool decodes input that already looks like Base64.
- Use the URL-safe alphabet for JWT-style segments, cookies, and query values.
- Emoji and accented characters encode correctly — everything goes through UTF-8 first.
Encoding, decoding, hashing, and UUID generation all run in your browser. The text and tokens you paste are never uploaded, stored, or logged.
What Base64 is (and is not)
Base64 converts bytes into 64 printable characters so binary or awkward text survives text-only channels: JSON fields, HTML data URIs, SMTP, logs. Every 3 bytes become 4 characters, so output is about a third larger than the input.
Base64 is an encoding, not encryption. Anyone can decode it instantly — never treat a Base64 string as protected. It is for transport, not secrecy.
Standard vs URL-safe
The standard alphabet uses + and /, which have reserved meanings in URLs and file names. The URL-safe variant swaps them for - and _ and drops the = padding, which is why JWTs and URL parameters always look slightly different from classic Base64.
This tool accepts either alphabet when decoding — paste a JWT segment, a padded string, or something with stray whitespace and it will still decode.
Frequently asked questions
Why does my Base64 output contain +, /, or = characters?
Those belong to the standard Base64 alphabet: + and / expand the character range and = pads the output to a multiple of 4 characters. Switch to the URL-safe option if the result will live in a URL, cookie, or file name.
Does encoding encrypt my data?
No. Base64 is trivially reversible — it only changes how bytes are represented, not who can read them. Use real cryptography for secrecy.
Is my text uploaded when I encode it here?
No. Encoding and decoding run in your browser with client-side JavaScript. Tokens and payloads never leave your device.