“What’s inside this token?”
If you’ve ever implemented authentication, you’ve definitely encountered that mysterious string starting with eyJhb.... That is a JWT (JSON Web Token).
“Is the user ID correctly included?” “Has the expiration time (exp) passed?”
When questions like these arise, you often need to quickly check the content of the token. But wait—where are you planning to decode that token?
There’s no such thing as “data that’s okay to be seen”
The Header and Payload of a JWT are simply encoded using Base64Url. They are not encrypted, meaning anyone can read their contents.
To check these contents, many developers turn to online debuggers. But what if that token belongs to a production environment? If you send a sensitive token to a malicious or insecure site, you risk an immediate session hijacking.
“I just want to debug, not take risks.” Our site was built specifically to fulfill that 100% reasonable wish.
Secure debugging, right in your browser
DevToolKits’ JWT Debugger analyzes your token entirely within your browser.
No data is ever sent to a server. You can even check this yourself by opening your browser’s network tab. Even when you click the button, the tool remains “silent.” This silence is the greatest peace of mind we can provide.
Usage Tips
- Paste the token you want to debug.
- Instantly view the expanded “Header” and “Payload.”
- Verify the signature (Verification) by pasting the secret or public key to check integrity if needed.
Conclusion
JWTs are powerful tools, but one wrong move can lead to a major security incident.
Always check your tokens in a safe environment. By adopting better habits, you can enjoy building more robust and secure systems.