The best Capture The Flag framework out there for


Hiring hackers


Training developers


Teaching students







Capture The Flags are the defacto way to learn complex security concepts


Want to run a hacking competition for your team?


We design and host custom challenges for your players to hack on and learn from


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It's easy to run a Capture The Flag

Here are some of our favorite features


Visualize your Teams

With all the visualization in CTFd you'll know what's going on with just a glance.

Control Everything

All you need to use to run your very own Capture The Flag is a web browser. Just use the built in administration panel and say goodbye to database queries.

Edit Everything

With its HTML editor, you can create entire pages inside of CTFd. Need to share lots of links? Make an FAQ? A contact page?
No problem.

Add Hints for those hard times

Hacking is hard work. If your users are stuck you can setup hints for them to get unstuck.

Clean but Customizeable

No clutter makes the default theme of CTFd a beauty without being opinionated. It works well but if you want something a little more you, there’s custom theme support built right in!

And save your CTF too

With the Import/Export feature, you can save your CTF and reuse all your hard work.









Check out a demo








For Security Teams


They say the best defense is a good offense. We believe that to protect against security threats, you have to know how they work.

There's no better way to learn offensive security than to play a Capture The Flag.

Put a Capture The Flag in your recruiting pipeline and hire better hackers and better engineers.

For Schools


CTFd was created for education at one of the oldest engineering institutions in the United States. One of its core focuses is helping educators teach students.

CTFd can be used to teach students programming, ask questions, and conduct automatic online assessments.









Best of all, CTFd is open source

Let's get started

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Some of our users