JWT Debugger

Decode and inspect your JSON Web Tokens.

HEADER: ALGORITHM & TOKEN TYPE
Waiting for token...
PAYLOAD: DATA
...
VERIFY SIGNATURE
Signature verification happens on the server. Do not paste sensitive production secrets here.

Decode and inspect JSON Web Tokens (JWT) locally. Check expiration claims without leaking production tokens.

Why This Tool Exists

JWTs are the keys to your kingdom. Pasting a production session token into a website like 'jwt.io' is a massive security risk if that site logs requests. PrivaQuickTools JWT Debugger decodes the Base64Url payload locally.
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I used to shudder every time I pasted a real token into an online debugger. I built this so I never have to worry about a third-party storing my user's session.

Key Capabilities

Core features that make this tool powerful.

Header/Payload Decode

Expiration visualizer

Signature Check (Local)

How It Works

Understanding the processing logic.

Client-side Base64 decoding of the 3 JWT parts.

Accuracy & Reliability

Standard JWT spec RFC 7519.

Who Is This For?

Backend Devs

Auth debugging.

Common Mysteries & Fixes

Signature Validation

We can only check signature format, not validity (we don't have your server secret).

Real-World Scenarios

Debugging

Why is my token invalid?

Why Choose PrivaQuickTools

FeaturePrivaQuickToolsOthers
Privacy100% LocalCloud

Privacy & Security Guaranteed

We do not store, view, or upload your files. All processing happens in your browser's memory. When you close the tab, all data is wiped from memory.

Good to Know

Large files depends on your device RAM. Processing massive video/PDFs may be slower on mobile devices.

Benefits

  • PrivacyTokens never leave your RAM.

When Not To Use

While we aim for perfection, browser-based tools have limits. This tool might not be the best fit for:

  • Extremely large files (e.g., video over 2GB)
  • Batch processing thousands of files at once
  • Workflows requiring server-side collaboration or cloud storage

Frequently Asked Questions

Common questions about this tool.

No. The code is client-side.