Best Free Online JWT Generator
Generating test JWT tokens during API development — to simulate authenticated requests, test authorization logic, or populate fixture data — is a common need that usually requires writing a small script. devtoolkit.sh's JWT Generator lets you configure the header, payload claims, signing algorithm, and secret or key directly in the browser and produces a signed JWT instantly. It supports HS256, HS384, HS512, RS256, and ES256. The generated token can be decoded immediately to verify its contents. All signing happens in your browser — your secrets and private keys are never transmitted. This is ideal for testing protected API endpoints, seeding authentication fixtures, and learning how JWT signing works.
HS256
| Claim | Value | |
|---|---|---|
FAQ
- Which signing algorithms are supported?
- HS256, HS384, HS512 (HMAC with SHA), RS256 (RSA), and ES256 (ECDSA) are supported. HS256 is the most common for API development.
- Can I set expiration and custom claims?
- Yes. The payload editor lets you add any claims including exp, iat, sub, aud, and custom application-specific claims.
- Is my signing secret safe?
- Yes. All cryptographic operations run in your browser. Nothing is sent to any server.