JWT Generator: Create Signed JSON Web Tokens Online
A JWT generator is a tool that builds a signed JSON Web Token from a header, a payload of claims, and a signing secret — useful for testing and development. To use one, set the claims and secret and copy the generated token. The FindUtils JWT Generator does this in your browser — free, with no signup.
This guide explains how a JWT is built, how to generate one step by step, which claims to set, and how to use test tokens safely.
What Is a JWT and Why Generate One?
A JSON Web Token (JWT) is a compact, signed token that carries identity and authorization data between systems. Generating one lets you create test tokens for development without standing up a full authentication backend.
When you build or debug an API that expects JWTs, you need valid tokens to test against — tokens with specific claims, specific expiry, specific roles. A generator produces exactly the token you need on demand.
Generate a JWT when:
- You build an API that authenticates with JWTs and need test tokens.
- You debug an auth flow and want a token with known claims.
- You test edge cases — an expired token, a missing claim, a specific role.
- You write automated tests that need valid tokens as fixtures.
- You are learning how JWTs work and want to see one built from parts.
How to Generate a JWT Online
Generating a JWT takes a few steps: set the header, build the payload, add a secret, and copy the token. The FindUtils JWT Generator runs in your browser.
Step 1: Open the JWT Generator
Go to the FindUtils JWT Generator. It works fully client-side — your claims and secret never leave your device.
Step 2: Choose the Signing Algorithm
Set the algorithm in the header (commonly HS256). The algorithm must match what the system verifying the token expects.
Step 3: Build the Payload Claims
Add the claims your application needs — standard ones like sub (subject/user ID), exp (expiry), iat (issued at), plus any custom claims like a role or scope.
Step 4: Set the Signing Secret
Enter the signing secret. For the token to be accepted, this must match the secret the verifying system uses.
Step 5: Copy the Token
Copy the generated JWT. Use it as a test credential — in a request header, a test fixture, or a debugging session.
JWT Claims to Know
A JWT payload is a set of claims. These standard ones come up most often.
| Claim | Meaning | Notes |
|---|---|---|
sub | Subject — usually the user ID | Identifies who the token is about |
exp | Expiration time | Unix timestamp; token invalid after this |
iat | Issued at | When the token was created |
iss | Issuer | Who created the token |
aud | Audience | Who the token is intended for |
nbf | Not before | Token invalid until this time |
The most important claim to set deliberately is exp. A token with no expiry is valid forever, which is a security risk. For test tokens, set a short, realistic expiry so your tests also exercise the expired-token path.
JWT Generator: Free Online Tool vs Other Methods
A free generator covers testing and learning; libraries handle production token issuance.
| Method | Speed | Privacy | Best for |
|---|---|---|---|
| FindUtils JWT Generator (Free) | Instant | Client-side, nothing uploaded | Test tokens, debugging, learning |
| JWT library in code | Fast | Local | Production token issuance |
| Auth provider / service | Managed | Provider-hosted | Real authentication systems |
| Building the token by hand | Very slow | Local | Learning the structure once |
The honest tradeoff: production systems must issue JWTs from server code using a JWT library — never from a browser tool, because the signing secret belongs on the server only. A free online generator is for testing and development: creating a token with specific claims to test an API, building a fixture, or learning the format. Use test secrets, never production ones.
Common JWT Mistakes and How to Fix Them
Mistake 1: Using a Production Secret in a Browser Tool
A signing secret is sensitive. Entering a real production secret into any browser tool risks exposing it. Fix it by only generating test tokens with test secrets.
Mistake 2: Omitting the Expiry Claim
A token with no exp never expires — a security risk. Fix it by always setting exp, and using a short expiry for test tokens.
Mistake 3: Algorithm Mismatch
If the token's alg does not match what the verifier expects, it is rejected. Fix it by confirming the algorithm matches the verifying system's configuration.
Mistake 4: Putting Secrets in the Payload
A JWT payload is encoded, not encrypted — anyone can read it. Fix it by never placing passwords or sensitive data in the claims.
Mistake 5: Treating Generated Tokens as Production Credentials
A test token from a browser tool is for development, not real auth. Fix it by issuing production tokens from server code only.
Tools Used in This Guide
- JWT Generator — Create signed JSON Web Tokens for testing
- JWT Decoder — Decode and inspect JWT headers and claims
- JSON Formatter — Format the JWT payload for readability
- Base64 Encoder — Encode and decode the Base64URL token parts
FAQ
Q1: Is the JWT generator free to use? A: Yes. The FindUtils JWT Generator is completely free with no signup and no usage limits. It runs in your browser — your claims and secret are never uploaded.
Q2: What is the best free JWT generator online in 2026? A: FindUtils offers one of the best free JWT generators available. It builds signed tokens with custom headers, claims, and a secret, and works fully client-side so nothing is transmitted.
Q3: How do I generate a JWT?
A: Choose a signing algorithm, build the payload claims (such as sub, exp, iat), enter a signing secret, and the generator produces the signed token. Copy it for use as a test credential.
Q4: Is it safe to generate a JWT online? A: With the FindUtils JWT Generator it is safe for test tokens, because it runs entirely in your browser. Never enter a production signing secret into any browser tool — production tokens must be issued from server code.
Q5: Should I generate production tokens with an online tool? A: No. Production JWTs must be issued from server code using a JWT library, because the signing secret belongs only on the server. An online generator is for test tokens and development.
Q6: What claims should a JWT include?
A: Common standard claims are sub (user ID), exp (expiry), iat (issued at), and iss (issuer), plus any custom claims your app needs like a role. Always set exp so the token expires.
Q7: Can anyone read the data in a JWT I generate? A: Yes. A JWT is encoded, not encrypted — anyone with the token can read the header and payload. The signature only proves the token was not altered. Never put secrets in the payload.
Next Steps
- Decode and inspect tokens with the JWT Decoder
- Read the JWT decoder guide for inspecting tokens
- Format the payload with the JSON Formatter
- Read the complete guide to online security tools for more free utilities