JSON formatter & validator
Format, beautify, validate, and minify JSON online. Pinpoint syntax errors by line and column, sort keys, and copy or download the result.
JWT decoder
Decode JSON Web Tokens to inspect the header and payload, check expiry, and verify HS256, RS256, and ES256 signatures — tokens never leave your browser.
Header
Payload
Verify signature
How to use JWT decoder
Paste a JSON Web Token to decode its header and payload, see when it was issued and when it expires, and verify the signature. Supports HS256/384/512 with a shared secret and RS256, PS256, and ES256 with a public key (PEM or JWK).
Decoding happens entirely in your browser. Tokens often grant access to accounts, so avoid pasting production tokens into tools that send them to a server.
JWT decoder FAQs
Is JWT decoder free?
JWT decoder is a free online tool on ReallyUseful.Tools. No account is required.
Does JWT decoder run in my browser?
JWT decoder is designed to run in your browser where supported, so files can stay on your device instead of being uploaded to a server.
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