JWT Decoder — Inspect JSON Web Tokens Online

Paste a JWT to decode its header, payload, and check expiration.

How It Works

  1. 1Upload your file by dragging it into the drop zone or clicking to browse.
  2. 2Adjust the quality slider to balance file size and visual fidelity (optional).
  3. 3Click Download to save your converted file.

About JWT Decoder

JSON Web Tokens (JWTs) are used for authentication and authorization across web applications. This tool splits a JWT into its three parts (header, payload, signature), decodes the Base64URL-encoded header and payload, and displays the JSON content with syntax highlighting. It also checks the exp claim and warns you if the token is expired. No data is sent to any server — the decoding happens entirely in your browser.

Frequently Asked Questions

Can this tool verify JWT signatures?

This tool decodes and displays the JWT header and payload, and checks expiration. It does not verify cryptographic signatures — that requires the signing secret or public key, which should never be pasted into a web tool.

Is my JWT token sent to a server?

No. The decoding happens entirely in your browser. Your token never leaves your device.

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