JWT Decoder

Paste a JSON Web Token to decode its header and payload instantly.

Last Updated: August 2026
100% Client-Side — Your data never leaves your device

Decoding is not Verification

This tool decodes the Base64URL encoded parts of the token so you can read them. It does NOT verify the signature. Do not trust the contents of a token in production unless you have verified its signature cryptographically.

Why this tool is safe

Your data never leaves your device — everything runs in your browser.

No server uploads. Other tools send your files to their servers. Ours don't.
Zero tracking of content. We never see, store, or log anything you convert.
Works offline. Once loaded, the tool works without an internet connection.
No account required. Instantly use all tools completely free without signing up.

What is a JSON Web Token (JWT)?

A JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object.

A JWT consists of three parts separated by dots (.): Header, Payload, and Signature. The Header and Payload are Base64URL encoded.

How our JWT Decoder Works

Our tool takes your JWT, splits it by the dots, and decodes the Base64URL payloads for the Header and Payload sections, displaying them as formatted JSON.

Because this decoding happens 100% locally in your browser, it is perfectly safe to decode tokens containing sensitive information. We never transmit your tokens over the network.

Frequently Asked Questions

Search below or browse through our most commonly asked questions.

A JSON Web Token (JWT) is a standard used to create access tokens for an application. It typically consists of three Base64URL-encoded parts separated by dots: a header, a payload, and a signature.
Because this tool processes everything client-side in your browser, your token is never uploaded or saved. However, you should never paste sensitive production tokens into public websites.

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