What Is Hacker101?

Updated

Hacker101 is a free web security class from HackerOne. It combines video lessons, written guides, and hands-on Capture the Flag (CTF) levels, and it is aimed at anyone from a programmer curious about bug bounties to a seasoned security professional. If you want structured, self-paced material that moves from concepts to practical exploitation, it is a reasonable starting point. If you need formal certification, instructor-led pacing, or a syllabus mapped to a specific exam, look elsewhere.

What you actually get

The site organizes its content around two main entry points, plus supporting material:

  • Video Lessons — free classes covering web security topics, with guides and resources alongside them.
  • Capture the Flag — CTF levels described as "inspired by the real world," intended for putting skills into practice.
  • Guides and resources — reference material that accompanies the lessons.

The stated audience is broad on purpose: the same platform is pitched at people who write code and want to try bug bounties, and at people who already work in security.

How the two halves fit together

The design assumes you alternate between learning and doing:

  1. Watch or read a lesson to pick up a concept — for example, how a class of input handling flaw arises.
  2. Attempt the related CTF level to apply it against a target you are allowed to attack.
  3. Return to the guides when you get stuck, then retry.

The CTF levels are the part that distinguishes Hacker101 from a pure video course. Because they are modeled on real-world scenarios, the skills transfer more directly to bug bounty work than puzzle-style challenges that reward trivia.

Who should use it

Your situation Hacker101 fits? Why
Programmer curious about bug bounties Yes Free entry point, practical levels, no cost to try
Working security professional brushing up on web topics Yes Material assumes you can handle technical content
Complete beginner with no coding background Partly Video lessons help, but CTF levels assume you can read and reason about code
Someone needing a certificate or exam prep No The site presents itself as a class, not a credentialed program
Someone wanting a fixed schedule and deadlines No It is self-paced

Practical things to know before starting

  • It is free. The site describes itself as "a free class for web security," and the lessons, guides, and CTF are presented as free resources.
  • It is self-directed. There is no stated schedule, cohort, or completion requirement, so you set your own pace and decide when a topic is "done."
  • The CTF is the core practice loop. Treat the videos as preparation for the levels rather than the end goal; the levels are where the real-world framing pays off.
  • Expect to get stuck. That is normal for CTF-style learning. The intended recovery path is the accompanying guides and lessons, not brute-forcing a single level for hours.

A sensible first session

If you are deciding whether to commit, spend one sitting like this:

  1. Open the Video Lessons section and pick one topic you already half-understand.
  2. Watch it, then immediately open the CTF section and try a level that touches the same idea.
  3. Note where you stall. If the stall is "I don't know this concept," the lessons are working as intended. If the stall is "I can't write the code at all," you may want to build basic programming and web fundamentals first.

That single loop tells you more about fit than reading any description, including this one.