2021

• Google CTF 2021 Beginners Quest

2019

• play.kaf.sh
• utc-ctf.club
• wtftime
• justctf
• xmasctf
• watevrctf
• tuctf.com
• ctf.ritsec.club
• nctf.vulnerable.kr
• hack.lu
• seccon.jp
• cryptixctf.com
• rootersctf.in
• ctf2019.syskron-security.com
• picoctf-2019
• sect-ctf
• nactf.com
• ctf.csaw.io
• affinityctf
• twctf
• pase.ca
• hackcon.online
• ctf.sec.army
• ctf.redpwn.net
• gctf-2019
• gctf-2018

Capturing flags for self-education in information security since July 2019.

0xf4b1 on ctftime.org