Inspect token claims
Read issuer, subject, audience and time-related claims while debugging authentication flows.
100% local · files never leave your browser
Inspect tool
JWT Decoder
Decode JWT headers and payloads locally in your browser. No token upload, account or signature-verification claim.
✓ Free to use✓ No signup✓ Runs locally
125 bytes · local only
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Processed entirely in this tab
Your input and result are not sent to JSON Hearth or stored on a server.
When to use it
What JWT Decoder helps you do
JWT decoding makes the Base64URL-encoded header and payload readable. It does not establish that a token is authentic or safe to trust.
Review token structure
Check the declared algorithm and payload shape without sending the token to a remote decoder.
Diagnose expiry issues
Inspect issued-at and expiration values as part of troubleshooting, while still verifying them in trusted code.
How it works
JWT Decoder, without the upload.
Add your data
Paste a value, open a local file or begin with the working sample.
Run the tool
The transformation executes in your browser, not on our servers.
Review the result
Check the output, then copy or download it for your next task.
Important limitations
What to check before using the result
Review required
Decoding does not verify the signature, issuer, audience, expiry or any authorization decision.
Review required
Treat bearer tokens as secrets and avoid sharing decoded or raw values unnecessarily.
Common questions
About JWT Decoder
Does JWT Decoder upload my data?
No. Your input is processed by code running in your browser and is not sent to an application server.
Is JWT Decoder free to use?
Yes. The tool is free, requires no account and can be used directly in the browser.
Does decoding a JWT verify its signature?
No. Anyone can decode the header and payload. Verification requires the correct key and trusted validation logic.
Can I trust claims shown by a decoder?
Only after a trusted system has verified the signature and enforced issuer, audience, expiry and application rules.