Axonix Tools
Client-Side Decoder

JWT Debugger

Decode, verify and debug JSON Web Tokens. Paste your token to view its header and payload instantly.

Encoded Token

Header

Algorithm & Token Type

{}

Payload

Data & Claims

{}

Signature

Verified Signature

HMACSHA256(
  base64UrlEncode(header) + "." +
  base64UrlEncode(payload),
  your-256-bit-secret
)

JWT Debugger

This JWT Debugger handles the messy work so you don't have to. Everything runs in your browser — no installs, no accounts, no fine print. To get going: Paste your JSON Web Token (JWT) into the input field on the left.

No signup neededRuns offlineZero data collection

Blazing fast

No server round-trips. No loading bars. Just instant results.

Locked-down privacy

Your data stays in your browser. Period.

Zero friction

Open the page and go. No accounts, no upsells, no clutter.

Built for people who value their time

Security auditorsDevOps engineersPenetration testersCompliance teams

The 30-second rundown

01

Drop it in

Paste text, upload a file, or enter your values.

02

Tweak if needed

Adjust a setting or two — most defaults just work.

03

Grab the result

Copy, download, or share. Done in seconds.

How This Works

Below is everything you need to get from zero to done. No fluff, just the steps and features that matter.

JWT DebuggerJWT Debugger onlinefree jwt debuggerjwt debugger tool
How to Use JWT Debugger
  • 1Paste your JSON Web Token (JWT) into the input field on the left.
  • 2Instantly see the decoded Header and Payload on the right.
  • 3The tool will automatically validate the token structure.
  • 4Header fields (like 'alg' and 'typ') are highlighted in red.
  • 5Payload data (claims) is highlighted in purple.
  • 6Use the Clear button to reset the tool and start over.
Key Features
  • Client-Side Only: Your secure tokens are decoded right in your browser memory and are never transmitted to any server.
  • Instant Parsing: See the decoded JSON structure immediately as you type or paste.
  • Visual Debugging: distinct color coding helps you understand the three parts of a JWT (Header.Payload.Signature).
  • Error Handling: Get clear feedback if your token is malformed or invalid.

Making the Most of It

Good times to reach for this: Reach for JWT Debugger when you're verifying tokens, checking hashes, or handling anything sensitive. Your data stays on your machine — no risky pasting into random servers.

Typical flow:

  1. Toss your content into the input — text, file, or whatever you're working with.
  2. Dial in the settings that match what you actually need.
  3. Glance over the output to confirm it looks right.
  4. Grab your result: copy, download, or send it along.

Easy traps to avoid:

  • Feeding in sloppy input and assuming the tool will magically sort out every edge case — always eyeball the output first.
  • Testing with toy data that looks nothing like your real workload, then getting caught off-guard in production.
  • Copy-pasting straight into a live project without a ten-second sanity check. That tiny pause saves hours of cleanup.

Your data stays yours: Your files never touch our servers for standard processing. They stay on your device from start to finish.

Questions That Usually Come Up

Dig Deeper

Want walkthroughs, deep-dives, and edge-case tips? The blog has you covered with practical tutorials written by people who actually use these tools.

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