1
Hackers101
hacker101.comSame kind of website
Hacker101 offers a free web security class with lessons and Capture the Flag challenges.
Alternatives
The Best CTF101 Alternatives in 2026
8 alternatives
Looking for something like CTF101? Here are 8 alternatives, ranked by how closely they match it on purpose, features and platforms.
The CTF101 wiki introduces Capture the Flag competitions and explains related security concepts.
Top picks at a glance
First suggestionHackers101Hacker101 offers a free web security class with lessons and…Another optionCTFtimeCTFtime lists upcoming and past Capture the Flag events…
Quick comparison
| # | Alternative | Pricing | Open source | Platforms |
|---|---|---|---|---|
| 1 | Hackers101 | — | Not stated | Web |
| 2 | CTFtime | — | Not stated | Web |
| 3 | CTF Sites | — | Not stated | Linux, Web |
| 4 | PHP Tutorial | — | Not stated | Web |
| 5 | CS50 | — | Not stated | Android, iOS, Web |
| 6 | The Book of Shaders | — | Not stated | Web |
| 7 | How DNSSEC Works | — | Not stated | Web |
| 8 | Trig for Games | — | Not stated | Web |
All CTF101 alternatives
2
CTFtime
ctftime.orgSame kind of website
CTFtime lists upcoming and past Capture the Flag events, teams, tasks, ratings, and writeups.
3
CTF Sites
ctfsites.github.ioSame kind of website
CTF Sites lists Capture the Flag sites and provides a directory for finding cybersecurity challenges.
4
PHP Tutorial
phptutorial.netSame kind of website
This PHP tutorial introduces building dynamic websites and web applications, from core language concepts onward.
5
CS50
cs50.harvard.edu/pythonSame kind of website
CS50’s Python course introduces programming with Python, covering code reading and writing, testing, debugging, and core concepts.
6
The Book of Shaders
thebookofshaders.comSame kind of website
A step-by-step guide introduces fragment shaders and shader programming concepts through a sequence of lessons.
7
How DNSSEC Works
howdnssec.worksSame kind of website
How DNSSEC Works explains DNS Security Extensions through an illustrated guide to its purpose and operation.
8
Trig for Games
demoman.net?a=trig-for-gamesSame kind of website
This interactive game development tutorial uses a homing rocket to explain trigonometry concepts.
No alternatives match this filter.
Alternatives to similar tools
CS5024 alternativesPHP Tutorial15 alternativesThe Book of Shaders11 alternativesHow DNSSEC Works14 alternativesTrig for Games12 alternativesHackers10115 alternatives
What is the best alternative to CTF101?
Based on features, tags and platforms, the closest alternatives to CTF101 are Hackers101, CTFtime, and CTF Sites.
Alternatives are suggested from the purpose and features described in our listings. Different pages for the same product appear once. Read each description to check whether it fits your task. How we choose alternatives · Suggest an alternative