JWT Inspector & Expiry Checker

100% In-Browser

100% private in-browser JWT debugger. Decodes header & payload, verifies signatures, and computes live relative token expiration.

Key Capabilities & Features

  • ✓ 100% Client-side processing with zero server telemetry
  • ✓ Instant copy and download options
  • ✓ Clean formatting and auto-validation
  • ✓ No account or subscription required

Frequently Asked Questions

Does my auth token leave my computer?

Never. Decoding, payload parsing, and signature verification are executed 100% in client-side browser memory. Zero telemetry or server calls are made.

How is relative expiration computed?

The inspector extracts the "exp" timestamp claim and calculates live human-readable countdowns (e.g. "Expires in 2 hours" or "Expired 3 days ago") in your local timezone.