JWT Decoder
Decode a JWT token and view the header and payload as JSON. Useful for debugging auth tokens. Runs locally in your browser.
Input
Output
Tip: You can verify in DevTools → Network that nothing is uploaded.
About this JWT Decoder
JWT Decoder splits a JWT into its parts and decodes the header and payload so you can inspect claims and metadata in readable JSON form.
This tool does not verify the signature — it is intended for inspection and debugging. Never paste secrets; decoding is local, but tokens may still contain sensitive information.
- Process text data quickly without external tools
- Transform content for development workflows
- Clean and format text for analysis
- Enable Auto to transform as you type
- Upload text files directly from your device
- Download the result when done
FAQ
No. Everything runs locally in your browser. Nothing you paste is sent to a server.
After the page loads once, it will typically keep working offline (unless you hard refresh with no cache).
No. Your input stays in your browser. Only optional preferences like theme or language may be stored.
Any plain text. You can paste text directly into the input box.
No. It decodes header/payload only. Signature verification requires a key and is out of scope for a simple decoder.
The token may be malformed or not Base64URL-encoded properly. Ensure it has three dot-separated parts.
Decoding runs locally, but JWTs can contain sensitive data. Avoid sharing or pasting tokens you don't control.