Decode JWT — Inspect Token, Local
Inspect the JSON header and claims carried inside a JWT without treating their presence as proof of identity. This view helps debug token structure before a separate verifier checks whether the token can be trusted.
- Runs in your browser
- Nothing is uploaded
- No signup; device limits apply
Numbers stay on your device. Nothing is sent to a server.
How to use this tool
Paste a dot-separated JWT, preferably a public test fixture first. Production access tokens may contain personal claims and carry usable credentials, so choose the input with the same care as a password.
Results and examples
A payload containing sub equal to 123 will still show that claim after decoding. An exp field describes an expiry claim; its presence does not establish a valid signature, expected issuer or accepted audience.
Limitations
- The tool reports a signature segment but does not cryptographically verify it.
- Encrypted JWE tokens require a different processing path and cannot be interpreted as ordinary signed JWTs.
Fields
| Field | Guidance and constraints |
|---|---|
| JWT | Check the unit and format displayed beside this field. |
Data handling
Processing stays in the current browser tab; the site does not upload tool input for the calculation itself.
Sources
Frequently asked questions
Does an exp claim prove validity?
A payload containing sub equal to 123 will still show that claim after decoding. An exp field describes an expiry claim; its presence does not establish a valid signature, expected issuer or accepted audience.
Is the signature checked?
The tool reports a signature segment but does not cryptographically verify it. Encrypted JWE tokens require a different processing path and cannot be interpreted as ordinary signed JWTs.
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