JWT Decoder & Inspector
Decode JSON Web Tokens locally in your browser. Inspect Header, Payload claims, and Signature verification status.
Decoded header JSON will appear here...Decoded payload JSON will appear here...📜 Recent Decoded JWT History
No recent tokens saved yet. Decode any JWT string above to save your history locally.
How to Use JWT Decoder
Decode and inspect JWT (JSON Web Token) header, payload and signature instantly. Displays expiry, issued-at, claims, and algorithm. No verification keys needed.
1. Input Data
Paste or upload your data into the tool. We support a variety of formats depending on the specific tool requirements.
2. Process
The tool will instantly process your data. All calculations and conversions are performed locally in your browser for maximum speed.
3. Get Results
Once the processing is complete, you can copy the results to your clipboard or download them as a file.
Frequently Asked Questions
Does the JWT decoder verify the signature?
No. This tool decodes (base64url decodes) the header and payload for inspection only. It does not cryptographically verify the token signature.
Is it safe to paste my JWT here?
All decoding is done in your browser — no data is sent to any server. However, treat JWTs as sensitive credentials and avoid pasting production tokens in public environments.
Frequently Asked Questions
Is this JWT Decoder tool free to use?
Yes, this tool is 100% free to use with no limits, no sign-up required, and no hidden fees.
Is my data secure?
Absolutely. We prioritize your privacy. All processing happens locally in your web browser (client-side). Your data is never uploaded to, stored on, or sent to any external server.
Does it work offline?
Yes, Base64Decoder.app is a Progressive Web App (PWA). Once the site is loaded, you can continue using this tool even without an internet connection.
