JWT Expiration Checker & Session Simulator
Pre-loaded with an already-expired token so you can see exactly how the exp claim is read, displayed, and flagged. Paste your own token to check its real expiry, or use the fast-forward controls to watch a live session die on schedule.
runs 100% in your browser — safe to paste real tokens
- 1Paste your tokenDrop a JWT — or a full Authorization header; the "Bearer " prefix is stripped automatically.
- 2Read the decoded claimsHeader and payload appear instantly as color-coded JSON. Nothing is uploaded or verified remotely.
- 3Simulate session deathWatch the live expiry countdown, then fast-forward time to see the token die on schedule.
headerpayloadsignature
Decoded locally with your browser’s native Base64 — the token never leaves this tab. The signature is displayed, never verified: this is a debugger, not a validator.
Session expiry timeline
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Fast-forward time
+0m
Header— algorithm & type
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Payload— claims
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