Base64 Decoder

About the Base64 Decoder

This decoder reverses Base64 strings back into readable text (when the payload was text). Use it to inspect data URLs, encoded config values, or tokens that were only encoded for transport.

How to use

1. Paste the Base64 string.
2. Decode it.
3. Read the resulting text or copy it into your editor.
4. If decoding fails, check for missing padding, URL-safe alphabet differences, or truncated input.

Troubleshooting failed decodes

• Whitespace or line breaks inserted by email clients
• URL-safe variants using - and _
• Incomplete strings copied from logs
• Binary payloads that look like garbage as “text” (expected for images/files)

Tips

• Remember: decoded output may still be sensitive. Handle secrets carefully.
• Pair with the encoder when you are building and verifying a pipeline end-to-end.

FAQ

Can I decode a JWT with this? JWT parts are Base64URL encoded. A dedicated JWT decoder is clearer because it splits header/payload/signature for you.