an image of a woman working on a laptop

Learn how to hack.

Explore dozens of free capture the flag challenges to build and test your skills while accessing hundreds of hours of video lessons. Meet other learners and get mentored by experienced hackers in the Hacker101 Community Discord channel.

What is Hacker101

What is Hacker101?

Hacker101 is a free class for web security. Whether you're a programmer with an interest in bug bounties or a seasoned security professional, Hacker101 has something to teach you. Learn to hack with our free video lessons, guides, and resources, plus join the Discord community and chat with thousands of other learners.

Earn Private Invitations with the Hacker101 CTF

Capture the Flag

Put your skills into practice with our 24x7 available Capture the Flag (CTF) levels inspired by real-world vulnerabilities. In each level you’re searching for a number of flags — unique bits of data — which you get by discovering and exploiting vulnerabilities. As you progress, you'll receive invitations to private bug bounty programs on HackerOne, jump-starting your bounty hunting career.

Hacker101 - Capture the Flag Competitions

CTF competitions

We regularly host puzzles and fun CTF challenges with the winners receiving cash prizes or invites to live hacking events. Follow Hacker0x01 on Twitter to never miss a CTF competition announcement, and join thousands of participants in the next global challenge.

Join the conversation and learn with other hackers.

Hacker FAQ

What will I learn?
  • How to identify, exploit, and remediate the top web security vulnerabilities, as well as many other arcane bugs
  • How to properly handle cryptography
  • How to design and review applications from a security standpoint
  • How to operate as a bug bounty hunter
Is it free?

Yes, it’s completely free of charge.

How do I access it?

Simply go to to get started.

Will there be new content added?

Yes! We regularly add modules and training materials, typically monthly so check back often for the latest.

I have a question on the course content.

You can email for questions related to the substance of the content.