Base64 Encoder / Decoder
Encode any text to Base64 or decode a Base64 string back to readable text. The conversion uses the browser's built-in codec and makes no network requests.
Runs locally — nothing you enter is sent
Utility
Free · no signup
Result will appear here
How to use
- Paste text (to encode) or a Base64 string (to decode) into the input.
- Click Encode or Decode.
- Copy the result.
Examples
Text
Hello, world!
Base64
SGVsbG8sIHdvcmxkIQ==
Supported formats
- Standard Base64 alphabet (RFC 4648) with padding.
Privacy
This tool runs entirely in your browser. Nothing you enter or open is sent anywhere. Privacy policy.
Limitations
- Input is treated as text, not binary files; non-Latin characters beyond Latin-1 may need URL-safe or UTF-8-aware handling in your own code.
- URL-safe Base64 variants (- and _) must be converted to +/ before decoding.
FAQ
Is Base64 encryption?
No. Base64 is an encoding, not encryption — anyone can decode it. Never use it to protect secrets.
Why does decoding fail with 'invalid input'?
The string probably contains characters outside the Base64 alphabet, has broken padding, or uses the URL-safe variant with - and _.