JWT Generator

Create an HMAC-signed JWT test token from a secret, issuer, subject, audience, expiration, and custom claims while the generated string stays copy-ready.

Create predictable HMAC JWTs for API tests before wiring a full identity provider.

Keep algorithm, secret, standard claims, custom claims, and generated token visible before copying.

  • Generate HMAC JWTs in the browser
  • Set issuer, subject, audience, expiration, and custom claims
  • Copy a signed JWT string for API testing

How to use JWT Generator

Choose an HMAC algorithm, enter development-safe claim values, generate the JWT, then test the token against the API or decoder that will inspect it.

  1. 1

    Choose algorithm and secret

    Select HS256, HS384, or HS512 and replace the sample secret with a development-only value that matches the API, middleware, or test harness you plan to use.

  2. 2

    Fill standard and custom claims

    Enter issuer, subject, audience, expiration minutes, and any string, number, or boolean custom claims that the receiving service expects for your exact test case.

  3. 3

    Generate and test the token

    Generate the JWT, copy the signed string, decode it for a quick claim review, then run it through the target API before sharing or saving the example.

HMAC algorithm selection

JWT Generator supports HS256, HS384, and HS512 so teams can match common shared-secret API tests without configuring RSA or ECDSA keys.

Standard JWT claim fields

Issuer, subject, audience, issued-at, and expiration values are placed into the payload so test tokens resemble real OAuth or application tokens.

Typed custom claims

Add string, number, or boolean custom claims for roles, scopes, tenant IDs, feature flags, or other API-specific values without editing raw JSON.

Browser Web Crypto signing

Signing runs in the browser with Web Crypto, keeping the secret and payload in the page while the generated token is prepared for copying.

Copy-ready generated token

The generated JWT stays visible in a copyable field so it can move directly into an Authorization header, Postman request, test fixture, or decoder.

Development safety checks

The surrounding notes call out weak sample secrets, production-key exposure, expiration behavior, and algorithm mismatch risks before the token leaves the page.

JWT Generator privacy and processing

JWT Generator signs tokens in the browser without an account, but the visible secret, claims, and generated JWT should still be handled as sensitive test material.

Processing Browser

JWT Generator uses the browser Web Crypto API to sign HS256, HS384, or HS512 tokens from the visible secret, standard claims, and custom claims without uploading values.

Storage None

Closing or refreshing JWT Generator clears the secret, claim fields, and generated token unless you copied them into your own secure development notes.

JWT Generator account access

JWT Generator does not need an account for development token creation; keep the session open while you finish because unsaved claim values clear on refresh.

Before You Use JWT Generator

Review these JWT Generator notes before creating bearer tokens for API tests, documentation examples, demos, local apps, or authentication debugging.

Privacy

Use development secrets and sample claims only; production signing secrets, private user data, and live customer identifiers should not be entered into an online generator.

The generated JWT may grant access in systems that trust the same secret, so copy, store, and revoke test tokens with the same care as other credentials.

Accuracy

JWT Generator creates a syntactically signed HMAC token, but it does not configure your API, identity provider, authorization policy, or key rotation.

Use the same issuer, audience, algorithm, secret, expiration, and claim names expected by the receiver or the generated token will fail validation.

Compatibility

This page supports HMAC signing with HS256, HS384, and HS512; RSA, ECDSA, JWK, PEM, encrypted JWE, and identity-provider issued tokens are outside this workflow.

Set expiration minutes to match your test case and remember that tokens without exp may be rejected by stricter APIs or security middleware.

Output

Decode the generated JWT before use to confirm alg, typ, iss, sub, aud, exp, iat, and custom claims landed in the expected payload shape.

Run the token in the actual API or local test harness before using it in docs, demos, automated tests, or handoff notes.

Limits

JWT Generator signs one HMAC JWT at a time in the browser; very large custom claims or weak device crypto support may slow signing preview.

Questions about JWT Generator

What is JWT Generator best for?

JWT Generator is best for API testing, local authentication demos, documentation examples, and claim-shape debugging where an HMAC-signed sample token is enough.

Which algorithms does JWT Generator support?

This page supports HS256, HS384, and HS512 HMAC signing with a shared secret. It does not generate RSA, ECDSA, JWK, PEM, or encrypted JWE tokens.

Should I use generated JWTs in production?

No. Use this generator for controlled testing and examples. Production tokens should come from your identity provider or backend signing service with secure key management.

Can I add custom claims to the generated token?

Yes. You can add string, number, or boolean custom claims, then decode the output to confirm each claim name and value matches the receiving API.

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