Decode Base64 back into readable text, accepting URL-safe input and missing padding. Your file never leaves this page. Everything happens in your browser, and there is no upload endpoint to send it to — that is checked by a build gate that fails if any network code reaches a tool’s bundle.
How to do it
- Paste the Base64 string.
- Read the decoded text.
- Press Copy.
Questions
It says my input decodes to a file rather than text. What does that mean?
The Base64 was valid, but the bytes behind it are not text — you have probably pasted an encoded image or another binary file. Showing it as text would produce a page of replacement characters, so the tool says so instead.
Do I need to add the padding back?
No. Missing = padding is restored automatically, and the URL-safe alphabet is accepted, so a JWT segment pasted straight in will decode.
Why does my decoded text have strange characters?
Usually because the original was encoded from a different character set. This page decodes as UTF-8, which is what almost everything uses.