Whether starting your info-sec journey or you’re a more experienced hacker, you need a safe and legal place to test your skills. Fortunately, the community has various free options to reach your potential. This article outlines a few of the many free ethical hacking labs and capture-the-flag services to test and better your skills. Check back for updated listings.

https://www.hackthebox.com
Hack The Box has been a staple in the ethical hacking community for years. They offer a variety of services. Hacking labs provide you with machines that you can attempt to hack on your own, or if you’re feeling competitive, you can step into the realm of capture the flag and either host your event or join others.

https://overthewire.org/wargames
OverTheWire provides 12 different wargames servers, with some having 20+ levels you can work through. If you are someone with a basic set of skills or someone with a more advanced understanding, these games have something for everyone. They also have an IRC and Discord server where you can discuss the related games or meet like-minded hackers who share a passion for wargames.

https://247ctf.com
247CTF currently has 71 challenges to test your hacking skills in cryptography, networking, reverse engineering, and exploitation. They aim to update and release new challenges from their team or community contributors. Upon completing challenges, users can rate them based on a difficulty scale ranging from very easy to very hard. They also provide a scoreboard to see where you compare against others.

https://hackthissite.org
Hack This Site was launched in 2003 to provide a secure legal environment for hackers to test their skills. This site offers basic challenges such as realistic websites, steganography, forensics, and other categories. Completing challenges increases your account’s score. Currently, their forum is offline, but they have an active Discord of 11k users.