JWT Signature Verification
Verify JWT token signatures using your secret key or RSA public key. Validate token authenticity locally.
How to Use JWT Signature Verification
Use this page when you need to verify JWT token signatures locally before trusting claims in a test or debugging workflow. It is built for searches like JWT verification, verify JWT token, validate JWT signature, check JWT signature, JWT verify token, JWT signature checker, and RS256 JWT verify where developers want a private browser-side check instead of uploading secrets.
- 1Paste or type your input in the left panel.
- 2Click Process or use the keyboard shortcut ⌘↵.
- 3View the result in the output panel. Use Copy to copy to clipboard or Download to save as a file.
Best use cases
- •Verify a signed JWT with a shared secret before using it in local auth testing or staging flows.
- •Check whether a token is expired, malformed, or signed with the wrong secret or public key during debugging.
- •Pair signature validation with decoded claims so you can inspect both the token contents and whether the token is authentic.
This tool processes data locally in your browser. Nothing is sent to external servers.
Examples
Token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9...
Secret: your-shared-secret
Expected checks: signature valid, exp present, role claim matchesWhat this JWT verification page is best for
- •This page focuses on JWT signature verification with either a shared secret or RSA public key, which matches high-intent searches like JWT verify, check JWT signature, and verify JWT token.
- •It is especially useful after generating a test token or when a staging login flow fails with an invalid signature error.
- •Because verification runs locally in the browser, tokens and shared secrets stay on your device while you debug auth issues.
Frequently Asked Questions
What does verification check?
It verifies that the JWT signature is valid for the given header and payload using your provided secret or RSA public key.
Is my secret key safe?
Yes. Verification runs entirely in your browser. Your secret never leaves your device.
What if verification fails?
The token has been tampered with, or the wrong secret was used.
Which algorithms are supported?
HS256, HS384, HS512, and RS256.
Does it check token expiration?
Yes, the tool also shows whether the token is expired based on the exp claim.
Can I use this to check or verify a JWT token online?
Yes. If you searched for check JWT signature, JWT verify token, or how to verify JWT token, this page is built for that exact validation workflow.
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