JWT inspector
Decode and inspect JWTs in your browser. Header, payload, and signature. Optional local verify if you paste a key. The token is not sent anywhere.
No uploads. No account. Free to use.
- Files never leave your device
- Runs entirely in your browser
- No signup required
- Free
What is jwt inspector?
A JWT inspector base64url-decodes the header and payload of a JSON Web Token in the page. The token is not posted anywhere.
How to use it
- Paste a JWT.
- Read decoded header and payload.
- Optionally paste a secret or public key to verify locally.
When to use it
Access tokens include subject, scopes, and sometimes PII. jwt.io-style debug should not require sending the token to a third party.
Notes
This page decodes. It does not verify signatures unless you later paste a key; unverified claims are not proof of authenticity.
Frequently asked questions
Are my files uploaded?
No. This tool runs in your browser. Files and text stay on your device and are not sent to our servers.
Does this use AI?
No. It is a deterministic utility. There is no model and no third-party processing of your data.
Is the token sent to a server?
No. Decoding is base64url in your browser. Verification, if you use it, also runs locally with the key you paste.
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