Base64 Decoder - Convert Base64 to Text

Base64 strings contain only A-Z, a-z, 0-9, plus (+), and slash (/) characters, often ending with = padding. The length is always a multiple of 4. If it matches this pattern, it might be Base64.

If the original data was binary (an image, compressed file, or encrypted data), decoding it as text will show unreadable characters. The decoder works correctly, but the data was never meant to be readable text.

Yes, you can decode the header and payload sections of JWT tokens (the first two parts separated by dots). The third part (signature) is binary and will not produce readable text.

URL-safe Base64 uses minus (-) and underscore (_) instead of plus (+) and slash (/) to avoid URL encoding issues. Some decoders handle both variants automatically.

Yes, all decoding happens in your browser - nothing is sent to any server. However, remember that Base64 is not encryption; anyone with the encoded string can decode it.

Common causes include invalid characters (spaces, line breaks), incorrect length (not a multiple of 4), or corrupted strings. Try removing any whitespace or checking for missing characters.