Validators
JWT Validator
Validate JSON Web Token structure and inspect JWT header and payload directly in your browser.
Tool
Validate JSON Web Token structure and inspect JWT header and payload directly in your browser.
This tool runs in your browser. Your input is processed locally and is not uploaded.
About this Tool
Use this free JWT Validator to check whether a JSON Web Token is formatted correctly. It can help detect missing token parts, invalid Base64URL encoding, malformed JSON in the header or payload, unsupported algorithms, and common token structure issues. The validation runs directly in your browser, so your token does not need to be uploaded to a server.
Examples
- eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjMifQ.signature
- eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJpc3MiOiJleGFtcGxlIn0.
Frequently Asked Questions
What does this JWT validator check?
It checks whether the JWT has the expected three-part structure and whether the header and payload can be decoded as valid JSON.
Does this verify the JWT signature?
No. This tool checks and decodes the token structure. Signature verification requires the correct secret or public key.
Is my JWT uploaded?
No. The validation is designed to run locally in your browser.