Free JWT Decoder Online
Decode JSON Web Tokens instantly using a secure browser-based JWT decoder. Inspect JWT headers and payloads locally without uploading tokens to servers.
This tool decodes JWT tokens only and does not verify signatures.
What is a JWT Token?
JWT stands for JSON Web Token. JWTs are commonly used for authentication, authorization and secure data exchange between applications and APIs.
A JWT token usually contains three parts: header, payload and signature. The payload often contains user claims, expiration times and permissions.
How to Decode a JWT
- Paste your JWT token into the input field
- Click Decode
- Inspect the decoded header and payload
- Review expiration dates and claims
JWT Privacy and Security
This JWT decoder works entirely in your browser. No tokens are uploaded or transmitted to external servers, making it safer for inspecting sensitive JWT data locally.
JWT Header vs Payload
The JWT header contains metadata such as the signing algorithm. The payload contains claims and application data such as user IDs, roles and expiration timestamps.
Important Security Note
Decoding a JWT does not verify its authenticity. A valid signature verification process is still required to trust a token.
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Frequently Asked Questions
What is a JWT token?
JWT stands for JSON Web Token and is widely used for authentication and API authorization.
Does this tool verify JWT signatures?
No. This tool only decodes JWT tokens and does not validate signatures.
Are JWT tokens uploaded to servers?
No. All JWT decoding happens locally in your browser.
Can I inspect JWT expiration dates?
Yes. Expiration claims such as exp are visible inside the decoded payload.