JWT Brute Force Tester Online - Test Weak HMAC Secrets | JavaInUse
🔐 JWT Brute Force Tester
Test if your JWT uses a weak or common HMAC secret
🔒
100% Client-Side - Your Token Never Leaves Your Browser
⚠Security Tool: This tool helps identify JWTs signed with weak secrets.
Use it only on tokens you own or have permission to test. Never use weak secrets in production!
Enter JWT Token
Paste a JWT signed with an HMAC algorithm (HS256, HS384, HS512) to test against common weak secrets.
Detected Algorithm:HS256
Payload Preview
Default wordlist: Contains 500+ common weak secrets including "secret", "password", "123456",
company names, common words, and known default secrets from various frameworks.
Testing secrets...
About JWT Brute Force Testing
JWT (JSON Web Token) security depends heavily on the strength of the secret key used for HMAC signing.
This tool tests your JWT against a comprehensive wordlist of common weak secrets to identify potential vulnerabilities.
HS256/384/512: HMAC-based algorithms that use a shared secret
Weak Secrets: Common passwords like "secret", "password", "123456"
Framework Defaults: Known default secrets from tutorials and frameworks
Dictionary Words: Common English words and company names
⚠ If a secret is found: Your JWT is vulnerable! Immediately rotate the secret key
and use a cryptographically strong random value (at least 256 bits for HS256).
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