JWT Decoder · free online developer tool

Decode JWT header and payload, verify HS256 signature. No install, opens instantly, works offline — data stays in your browser.

How to use JWT Decoder

1. Open this page (or search “JWT Decoder” on www.258tool.com).
2. Enter your input in the tool panel — results update instantly.
3. Copy, download or save as needed; your data is stored locally on this device.

FAQ

Is JWT Decoder free?

Completely free. No sign-up, no account — open and use.

Is my data uploaded to a server?

No. All processing runs locally in your browser; data stays on your device.

Does JWT Decoder work offline?

Yes. After the first visit, add 258tool to your home screen and everything works offline.

ReferenceRFC 7519(JSON Web Token)规范 · https://www.rfc-editor.org/rfc/rfc7519

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