Dev
Mock JWT Token Generator
Testing JWT handling without a real auth server means you need tokens that are structurally plausible — three dot-separated base64url parts, a standard header, recognisable claims — but cryptographically inert. This tool emits exactly that: a well-formed token you can decode and inspect without any risk of accidentally using it as a real credential. The generated token has an HS256 header, a payload with sub, name, iat, and exp claims, and a random 43-character signature segment. The header and payload are genuine base64url-encoded JSON, so any JWT debugger or decoder will parse them correctly. The signature is random bytes and will fail verification, which is the intended behaviour for a mock. Paste the token into an Authorization header in a test request, feed it to a decoder to inspect the shape, or use it in a unit test for token-parsing code. Because the signature does not verify, it is safe to commit to a test repo or share in documentation without exposing any real secret.
How to use
- Choose your options above
- Click Generate
- Copy your result
Detailed instructions
- Click Generate to produce a mock JWT.
- Copy the token into your test or request.
- Decode it to inspect the claims.
- Generate another whenever you need one.
Use Cases
- •Testing JWT parsing and decoding
- •Building mock authenticated API requests
- •Demoing an auth flow without a real server
- •Filling a token field in sample data
- •Inspecting how a debugger shows a JWT
Tips
- →Use it to test parsing, never as a credential.
- →The signature is random and will not verify.
- →Decode it with any JWT debugger.
- →Keep real tokens out of tools and demos.
FAQ
is this a real, valid JWT
It is structurally valid — three base64url parts with a proper header and standard claims — but the signature is random, so it will fail verification. It is meant for testing how code parses and handles tokens, not as a working credential.
what claims does the payload contain
The payload includes sub (a random 12-character string), name ("Test User"), iat (a random Unix timestamp), and exp (iat plus 3600 seconds). These are standard JWT claims that cover the fields most token-handling code expects to find.
why not use a real JWT for testing
Real tokens carry real secrets and can grant access, so pasting them into tools or sharing them is risky. A mock token gives you the same shape for testing parsing and display, with none of the security exposure of a live credential.
You might also like
Popular tools from other categories that share themes with this one.
Try these next
More free tools from other corners of the catalog, picked by shared themes.