JWT Generator
Sign JWTs with HS256/384/512 or verify a signature.
Signed and verified with the Web Crypto API in your browser. Your secret never leaves this page.
How to use
- 1Enter the payload claims as JSON.
- 2Choose the algorithm and enter or generate a secret.
- 3Add iat and an expiry if needed; the token updates live.
- 4Switch to Verify to check a token's signature with a secret.
Frequently asked questions
Which algorithms are supported?
HMAC algorithms HS256, HS384 and HS512. RSA and ECDSA (RS256, ES256) need private keys and aren't supported here.
Is my secret sent anywhere?
No. Tokens are signed with the Web Crypto API in your browser.
What are iat and exp?
iat is the issued-at time and exp the expiry time, both in Unix seconds. Servers reject a token after exp.
How long should the secret be?
For HS256 use at least 32 random bytes. Use the generate button for a strong one.
How do I just read a token?
Use our JWT Decoder to see the header and payload without a secret.
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