JWT Decoder
Paste a JSON Web Token (JWT) to inspect its header and payload in a nicely formatted JSON view. Decoding is done entirely in your browser, without signature verification and without sending any data to a server.
Usage note: Processing happens directly in your browser; your data is not sent to our servers. Avoid entering sensitive, personal, or illegal content. Privacy Policy and Terms for more details.
🔐 JWT utility for backend & frontend developers100% free, runs entirely in your browser
What is the JWT Decoder from SONO-Solutions?
The JWT Decoder from SONO-Solutions is an online tool for decoding JSON Web Tokens (JWT) directly in your browser. It lets you inspect the header and payload as formatted JSON, without sending tokens to any server and without verifying signatures.
When is a JWT decoder useful?
- • Inspecting claims like
sub,exp, andscope. - • Verifying that token payloads match your expectations during testing.
- • Debugging login/authorization issues in dev or staging environments.
- • Teaching teammates how JWTs work with real-world examples.
Features of the SONO-Solutions JWT Decoder
- • Decodes JWT header and payload into nicely formatted JSON.
- • Uses base64url decoding directly in your browser (no uploads).
- • Highlights the header.payload.signature structure.
- • Makes common claims easy to read at a glance.
- • Completely free, with no sign-up or usage caps for normal use.
How to use the JWT Decoder safely
- 1. Copy a JWT (typically in the form
xxx.yyy.zzz). - 2. Paste the token into the input on this page.
- 3. The tool splits the token into header, payload, and signature.
- 4. Inspect the decoded header and payload as formatted JSON.
- 5. Use the claims for debugging or manual verification.
Important: this decoder does not verify signatures. It only helps you read the contents of a token — it does not prove that the token is valid or trustworthy. For production security, always verify JWTs using your backend stack and library support.
Practical use cases
- • Checking why a token expires too quickly (reading
exp). - • Inspecting roles/permissions stored in custom claims.
- • Confirming issuer/audience settings match your IdP configuration.
- • Onboarding junior developers to JWT-based authentication patterns.
Frequently asked questions about the JWT Decoder
Is the JWT Decoder free to use?
Yes. The JWT Decoder and all tools on SONO-Solutions are free to use directly in your browser — no accounts, no subscriptions, and no paywalls.
Are my tokens uploaded or stored on a server?
No. All decoding happens locally in your browser using JavaScript. Your JWTs are not uploaded to or stored on SONO-Solutions servers, which is safer for sensitive tokens — though you should still be cautious when sharing tokens anywhere.
Does this tool validate that my JWT is secure and valid?
No. This tool only decodes and displays the token contents. It does not verify signatures, check against keys, or enforce any security rules. For real validation, rely on your backend JWT libraries and best practices.
Quick Guide
Use the tool or form on this page when you need to complete the task described at the top. If you are unsure whether this is the right tool, check the short description and the examples below to confirm it delivers the output you need.
How to Use
- Read the tool description to understand its main function and limits.
- Provide the requested input (text, file, or selection) following the examples.
- Hit the primary action button above (e.g., Generate/Convert/Analyze).
- Review the output; iterate with adjustments if necessary.
- Use copy/download buttons when available to save the result.
Sample Input & Output
- Input: raw text, a URL, or a file as instructed above.
- Output: formatted content, a new file, or a visual preview ready to use.
- Check any notes on the page for size or data-type limits.
Quick FAQ
- What should I do if the result looks wrong? Try a different example input, clean up the formatting (remove extra characters), and run it again.
- Is this tool free to use? Yes, the main features are available without signing up.
- Can I use it on mobile? Most tools are optimized for smaller screens.
Security & Privacy
Most processing happens in your browser, so data is not sent to the server unless explicitly noted on the page. Avoid entering sensitive or confidential information, and clear results after use if the device is shared.