JWT Decoder
Inspect a JWT header and payload locally without verifying its signature.
Ready. Processing happens on your device.
Maximum 2 MB per text file. CSV limits: 20,000 rows and 200 columns. Drop one supported text file onto the input.
How to use JWT Decoder
- Type or paste your input, open a supported local file, or try the example.
- Choose the available options and select Run tool.
- Review the output, then copy it or download it.
What to expect
Decoding does NOT verify the signature, issuer, expiry or authenticity. Never treat decoded claims as trusted.
Common questions
Does JWT Decoder send my input to a server?
No. Processing runs in a browser worker. Files are read locally and downloads are created on your device.
What if the result is empty or an error appears?
Check the input format and options. A filter or extraction may legitimately return no matches. Invalid formats show an explanation, and expensive operations stop after five seconds so you can revise the input.