This decoder turns a standard Base64 string back into the text it was made from, reading the decoded bytes as UTF-8. It is the counterpart of the Base64 encoder, and it is handy for inspecting a JWT payload, a data URI, or a value pulled out of a config file.
How to use
- Paste the Base64 string. Line breaks inside it are fine.
- The string is decoded and the resulting bytes are read back as UTF-8.
- Copy the decoded text.
FAQ
Why does it say the input is invalid?
A Base64 string uses only A–Z, a–z, 0–9, + and / with optional = padding, and its length must be a multiple of 4. A stray character or missing padding will stop it from decoding.
Can I decode a JWT with this?
You can decode the header and payload, but split the token at the dots first — a JWT is three Base64url segments joined by “.”, not a single Base64 string. Decoding also does not verify the signature.
Will it recover a file?
No. This returns text. If the original data was an image or another binary file, use a Base64 to file converter instead.