JWT Decoder
Paste a JWT to see the decoded header and payload (pretty-printed JSON), plus expiry status. Browser-only — your token never leaves your device.
100% in your browser. Files never uploaded.
How to use
- 1Paste a JWTThree dot-separated Base64URL parts.
- 2Read the decoded header and payloadPretty-printed JSON. Expiry is highlighted if present.
- 3Copy any sectionOne click per section.
FAQ
Is the token uploaded?
No. JWT decoding happens entirely in your browser using the native atob/TextDecoder. The token never leaves your device — important since JWTs often carry session credentials.
Does it verify the signature?
No — V1 only decodes. Signature verification requires the secret or public key, which is sensitive enough to merit its own tool. On the roadmap.