A friendly introduction to the open-source tool that’s making JWT security testing both safer and smarter

Hey there, fellow security enthusiasts! 👋

Let me tell you a story that might sound familiar. Just last week, I came across a LinkedIn post where a security professional mentioned seeing at least three new JWT analyzers making the rounds on social media. Pretty cool, right? These tools are definitely helpful for understanding JWT structure and vulnerabilities.

But here’s the thing that got me thinking (and probably keeps you up at night too): Are we being a bit too casual about where we’re testing our JWT tokens?

Imagine this: You’re working on a security assessment, you’ve got a JWT token from a client’s application, and you quickly paste it into the first online analyzer you find. Seems harmless enough… until you realize what just happened:

• That token might contain sensitive user information, email addresses, or role assignments
• Your token just traveled across the internet to someone else’s server
• You might have unknowingly violated privacy regulations
• An attacker could potentially intercept that data

I don’t know about you, but I definitely don’t want to wake up to my manager asking, “Did we just accidentally expose client data?” 😅

Say Hello to JWTAuditor — Your Privacy-First JWT Testing Companion

That’s exactly why we created JWTAuditor! Think of it as your friendly neighborhood JWT security expert that never gossips about your tokens because everything stays right in your browser.

Me and my friend Sandeep are both into pentesting, and we were honestly tired of stressing over token privacy. So we built our own thing — a tool that gives you full JWT security analysis without ever sending your tokens anywhere. Just local, just safe.

What Makes JWTAuditor Special (And Why You’ll Want to Use It)

Here’s the best part — your JWT tokens never leave your browser! Seriously, we process everything locally on your machine. No mysterious server uploads, no sneaky data collection, no “oops, we got hacked and your tokens were exposed” scenarios. It’s like having a personal JWT expert sitting right next to you.

🛡️ It’s Really, Really Smart

JWTAuditor automatically checks for over 15 different types of vulnerabilities. It’s like having a security consultant who never gets tired and remembers every possible JWT attack:

• Spots dangerous algorithm choices (like the infamous “none” algorithm)
• Finds sensitive data that shouldn’t be there (yes, it’ll catch credit card numbers!)
• Checks for missing security claims that could bite you later
• Detects header injection vulnerabilities
• Analyzes token lifetimes and replay attack potential

⚡ Built-in Brute Force Testing

Want to know if your JWT is using a weak secret? JWTAuditor comes with a wordlist of over 10000+ common secrets that attackers love to try. You can even upload your own wordlist if you’re feeling adventurous! The best part? It uses Web Workers, so it won’t freeze your browser while it’s working.

✏️ Token Editing Made Easy

Need to modify a token for testing? JWTAuditor has a beautiful visual editor with syntax highlighting. You can even generate RSA key pairs right in your browser for testing asymmetric algorithms. It’s like having a Swiss Army knife for JWT manipulation.

Why Open Source Makes All the Difference

Here’s something we’re really proud of: JWTAuditor is completely open-source! You can check out all the code on GitHub. “But why should I care?” you might ask. Great question!

Trust, But Verify

Remember when I said your tokens never leave your browser? Well, you don’t have to just take our word for it! You can actually look at the code and see for yourself. No hidden backdoors, no sneaky data collection, no “trust us, we’re the good guys” moments. It’s all there in plain sight.

The Community Has Your Back

Being open-source means developers and security experts from around the world are constantly looking at our code, finding bugs, and making improvements. It’s like having a giant team of security reviewers who never sleep!

Run It Your Way

Want to run JWTAuditor on your company’s internal network? Go for it! Need to customize it for your specific needs? Have at it! With open source, there are no hidden costs, no surprise licensing fees, and no “oh, by the way, we’re changing our terms of service” emails. What you see is what you get, and what you get is free forever.

Learning Hub

We didn’t just build a tool — we built a learning platform! JWTAuditor includes:

Easy-to-understand explanations of JWT fundamentals

• Detailed vulnerability descriptions (written in plain English, not security jargon)
• Step-by-step attack technique walkthroughs
• Guidelines for secure JWT implementation
• Tool-specific usage guides

Ready to Try JWTAuditor? Here’s How to Get Started

Option 1: Jump Right In (The Easy Way

Just head over to jwtauditor.com and start using it immediately! No downloads, no installations, no complicated setup. Remember, even though it’s web-based, everything happens in your browser — your tokens never leave your computer.

Option 2: Run It Locally (The Developer Way)

Want to run it on your own machine? No problem! Here’s how:

git clone https://github.com/dr34mhacks/jwtauditor.git
cd jwtauditor
# Serve locally (Python 3)
python -m http.server 8000
# Or with Node.js
npx serve .
# Open in browser
open http://localhost:8000

Option 3: Enterprise Deployment (The Corporate Way)

Need to deploy this for your whole team? We’ve got you covered:

• Host it on your internal web servers
• Integrate with your existing security tools
• Customize it for your organization’s specific needs
• Keep everything behind your firewall for maximum security

The PortSwigger Lab Challenge

Speaking of fun discoveries, we actually used JWTAuditor to solve one of the JWT labs from PortSwigger Web Security Academy, and it worked like a charm — no other tools needed! It helped us spot the issue, tweak the token, and finish the lab all in one place. We even made a YouTube video showing the whole process so you can check it out and try it yourself. Super handy and fun to use!

It’s always satisfying when your own tool helps you ace a security challenge. Kind of like a chef enjoying their own cooking! 👨‍🍳

Wrapping Up: Why JWTAuditor Just Makes Sense

Look, we live in a world where data privacy and security matter more than ever. JWTAuditor gives you a way to do comprehensive JWT security testing without the anxiety of wondering where your tokens ended up.

Ready to Give It a Try?

Don’t just take our word for it — try JWTAuditor for yourself!

• Start testing now: jwtauditor.com
• Check out the code:

• Learn more about JWTs: https://jwtauditor.com/docs/

Remember: Your JWT security is only as good as the tools you use to test it. Choose tools that respect your privacy, provide comprehensive analysis, and help you sleep better at night.

JWTAuditor — Because your tokens deserve better security (and so do you!).

Signing Out!