Hacker101 offers a free web security class with lessons and Capture the Flag challenges.
CTF Sites
vsCTFtime
CTF Sites vs CTFtime
How do CTF Sites and CTFtime compare? Here are the facts side by side: pricing, platforms, open-source status and what each one is for.
| Directory detail | CTF Sites | CTFtime |
|---|---|---|
| What it is | CTF Sites lists Capture the Flag sites and provides a directory for finding cybersecurity challenges. | CTFtime lists upcoming and past Capture the Flag events, teams, tasks, ratings, and writeups. |
| Website | ||
| Type | Website | Website |
| Topic | ||
| Pricing | Not confirmed | Not confirmed |
| Platforms | Linux, Web | Web |
| Open source | Not stated | Not stated |
| Language | — | English |
| Alternatives |
Other options to consider
Sites similar to both CTF Sites and CTFtime.
The CTF101 wiki introduces Capture the Flag competitions and explains related security concepts.