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JWT Signature Verification
Verify JWT token signatures using your secret key. Validate token authenticity locally.
All processing happens in your browser. Your data never leaves your device.
How to Use JWT Signature Verification
- 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.
This tool processes data locally in your browser. Nothing is sent to external servers.
Examples
Example input
# Example for JWT Signature Verification
# Paste your content in the input panel above to get started.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.
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, and HS512.
Does it check token expiration?
Yes, the tool also shows whether the token is expired based on the exp claim.