Dev
Générateur de JWT factices
A dummy JWT generator produces realistic-looking JSON Web Tokens — three dot-separated, base64url-style segments — that are perfect for testing token handling without exposing a real secret or a valid signature. Use them to check that your code splits a token into header, payload, and signature, stores it correctly, sends it in an Authorization header, or rejects it during signature verification. Pick a role claim such as user, admin, or guest so your fixtures cover different access levels. These tokens are not signed with any real key and will never pass genuine verification, which is exactly what you want for safe, repeatable tests. Generate one, copy it, and drop it into your mock requests or test data.
How to use
- Choose your options above
- Click Generate
- Copy your result
Detailed instructions
- Choose the role claim you want the token to represent.
- Click Generate to produce a realistic-looking dummy JWT.
- Copy it into your test request, fixture, or documentation.
- Use it to verify token parsing and transport, not real authentication.
Use Cases
- •Testing how your client stores and sends bearer tokens
- •Verifying that token-parsing code splits header, payload, and signature
- •Fixtures for tests that expect an Authorization header
- •Confirming your server rejects unsigned or invalid tokens
- •Placeholder tokens in API documentation and examples
Tips
- →Use these to confirm your server correctly rejects tokens with invalid signatures.
- →Generate tokens with different roles to test access-control branches.
- →For real authentication tests, mint tokens with your actual signing key in a sandbox.
- →Never paste a dummy token where a genuinely valid one is required.
FAQ
are these real jwts that will authenticate
No. These tokens have the correct three-part shape but are not signed with any real key, so they will fail genuine signature verification. They are for testing token handling and storage only, never for authenticating against a real service.
what are the three parts of a jwt
A JWT has a header, a payload, and a signature, joined by dots and each base64url-encoded. The header names the algorithm, the payload carries claims like the subject and expiry, and the signature lets a server verify the token was not tampered with.
why test with a fake token instead of a real one
Real tokens contain valid signatures tied to a secret and often expire quickly, which makes them awkward and unsafe to hard-code into tests. A dummy token gives you a stable, shareable value to exercise parsing and transport logic without leaking anything.
What is inside a JWT payload?
The payload (the middle section) holds claims — statements about the user and token, such as sub (subject/user id), iat (issued-at), exp (expiry), and any custom data — base64url-encoded, not encrypted. The generator builds tokens with that realistic three-part structure so you can test decoding and claim-reading; because the payload is only encoded, never put real secrets in a JWT.
Are JWTs encrypted?
By default, no — a standard signed JWT (JWS) is base64url-encoded and signed to prove it was not tampered with, but anyone can read the payload, so it offers integrity, not confidentiality. Only the separate JWE standard encrypts. The generator produces fake signed-style tokens for testing; treat their contents as readable, and never store sensitive data in a real JWT payload expecting it to be hidden.
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