Free Local utilities
JWT decoder
Decode a three-part JWT and inspect its header, claims and expiration. No signature verification is performed; decoded claims are untrusted.
Bookmark
Use your browser’s bookmark command to save this page. It saves the tool link, not your inputs or results.
Only the tool link is copied. Inputs and results are never included.
Your inputs
Runs in your browser. Inputs and results are not uploaded or saved by this tool. Copy or download only what you intend to keep.
Decoded claims are untrusted. A readable token or an unexpired date does not verify its signature or grant access.
Text input: up to 256 KiB. Results are cleared when you leave the page.
How it works
Header and payload are decoded as UTF-8 JSON. Numeric exp, iat and nbf claims use Unix seconds. Compare exp/nbf with the selected UTC reference (or device clock) and 0–300 seconds of tolerance. These are unverified claim comparisons, never signature or authorization checks.
Assumptions and limitations
Up to 256 KiB. Encrypted five-part tokens are unsupported. Decoded claims are attacker-controlled; expiry alone does not establish authenticity, issuer, audience or authorization. Device clock errors can affect expiry display.
How to use this tool
Paste a three-part token and choose Analyze. Review the header, payload and expiry separately. The example is synthetic and deliberately expired.
Worked example
Demonstration data only. Loading an example replaces the inputs but does not run the tool.
eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJzdWIiOiJleGFtcGxlIiwiZXhwIjowfQ. exp: 0
Frequently asked questions
What should I check before using this result?
Up to 256 KiB. Encrypted five-part tokens are unsupported. Decoded claims are attacker-controlled; expiry alone does not establish authenticity, issuer, audience or authorization. Device clock errors can affect expiry display.
Are my inputs or results saved automatically?
No. Processing stays in this browser and leaving the page clears the tool state. Copied or downloaded results remain under your control. Page-loading and privacy controls are described in the Privacy Policy.
Processing and privacy
No. Processing stays in this browser and leaving the page clears the tool state. Copied or downloaded results remain under your control. Page-loading and privacy controls are described in the Privacy Policy.
Privacy PolicyHelp
Paste a three-part token and choose Analyze. Review the header, payload and expiry separately. The example is synthetic and deliberately expired.
Runs in your browser. Inputs and results are not uploaded or saved by this tool. Copy or download only what you intend to keep.
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