JWT Decoder
Read a JWT header and payload locally without treating it as verified.
Important: Decoding a JWT does not verify its signature or authenticity.
How to use this tool
- Paste a three-part token and decode it, then inspect the JSON fields.
- Review the live result and use Copy result when you need to share it.
How the transformation works
Base64URL decoding does not check a signature, issuer, audience or authenticity. Processing runs entirely in this browser. The page does not upload, persist, execute or remotely inspect the supplied content.
Processing rules
Base64URL decoding does not check a signature, issuer, audience or authenticity. Processing runs entirely in this browser. The page does not upload, persist, execute or remotely inspect the supplied content.
Step-by-step transformation
- Paste a three-part token and decode it, then inspect the JSON fields.
- Base64URL decoding does not check a signature, issuer, audience or authenticity. Processing runs entirely in this browser. The page does not upload, persist, execute or remotely inspect the supplied content.
- Check the displayed result, then copy it if needed.
Worked example
A sample unsigned token reveals its algorithm and expiry claim.
Risk guidance
Frequently asked questions
Does this tool send my inputs anywhere?
No. The interactive calculation runs in your browser and this site does not submit tool inputs to a backend.
How should I use the result?
Check that the entered units and values match your situation, especially around dates, breaks, and rounding.
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