Decode base64 to text
Paste base64 and get the decoded UTF-8 text in the browser. Runs in this tab. Your inputs stay in this browser.
Input
Base64 text. Spaces, tabs, line feeds, carriage returns, U+2028 and U+2029, and the other characters JavaScript counts as white space, such as the no-break space, are ignored anywhere in the input. The next line character U+0085 is refused. Padding is optional, but when it is there it must be complete and only at the end. A length that leaves one character over a multiple of four is refused.
Output
The decoded UTF-8 string. Base64 that decodes to bytes that are not UTF-8 text, such as an image, is refused. A byte order mark at the very start of the text is dropped.
Limits
- Standard base64 only. The URL safe letters
-and_are refused. - Up to 1 MB (1,048,576 bytes) of input, spaces and line breaks included.
- No binary file download.
How this was made
The core transform was written by hand into the stub registry.
Errors
Every error names the field, the rule, and shows a small valid example.
Inputs not stored
This runs in your browser tab. Your inputs are not uploaded or stored. The tool sets no cookie, uses no local storage and sends no analytics about your inputs.