A JSON Web Token is a compact, URL-safe way to carry JSON claims between parties, usually signed so a server can verify integrity and authenticity.

How do I decode a JWT?

Paste the token above. This tool Base64URL-decodes the header and payload and shows them as JSON.

What are the header, payload and signature?

The header describes the token type and algorithm. The payload holds claims. The signature protects the first two parts when verified with the correct key.

Can I decode a JWT without the secret key?

Yes. Header and payload are encoded, not encrypted, in standard signed JWTs. The secret is required to verify—not to read—those sections.

Is it safe to paste a JWT into an online tool?

This decoder works offline in your browser, but tokens can grant access. Prefer non-production samples, rotate anything sensitive, and never paste long-lived secrets you cannot revoke.

A free online tool that inspects JWT header and payload data for debugging and learning.

How does the JWT Decoder work?

It splits the token on dots, Base64URL-decodes the first two parts, parses JSON, and surfaces warnings such as expiry—without verifying the signature.

How do I use the JWT Decoder?

Paste a JWT, review header and payload panels, and read the safety warnings before you act on the claims.

Is this JWT Decoder free to use?

Yes. It is free with no sign-up.

Can I use the JWT Decoder on mobile?

Yes. It works in mobile browsers for on-the-go debugging.

Free JWT Decoder Online, Inspect Header & Payload

Free JWT Decoder Online, Inspect Header & Payload | Binary Tech