Zero-network guarantee: open your browser Network tab and reload. After this page and its libraries load, decoding and verifying a token makes no network requests. The token is never put in the URL.
Header
{}
Payload claims
Expiry
Decode a token to see its expiry status and countdown.
Verify signature (WebCrypto, local only)
Compare two tokens
Runs 100% in your browser. Your files never leave this device.
How it works
- Decodes header and payload locally and humanises registered claims: exp, iat and nbf become local and UTC times with a live countdown.
- Verifies HS256, RS256 and ES256 signatures with WebCrypto in the page. Nothing is sent to a server.
- Paste two tokens to get a claim-by-claim diff of what changed.
- Redacted copy masks the signature and sensitive claims, safe to paste into a support ticket.
- Works offline after load. Decoding is not verification, so always verify before trusting a token.