There are several reputable platforms that offer free courses for learning cybersecurity. Here are some of the top platforms:

1. Cybrary ( Cybrary offers a wide range of free cybersecurity courses, including beginner-level courses and more advanced topics. They cover areas such as network security, ethical hacking, penetration testing, and digital forensics.

2. OpenSecurityTraining ( OpenSecurityTraining provides free access to a collection of video lectures and course materials on various aspects of cybersecurity. They cover topics like malware analysis, reverse engineering, and network security.

3. edX ( edX is a popular online learning platform that offers a variety of free cybersecurity courses from top universities and institutions. They cover topics such as cryptography, cybersecurity fundamentals, and secure coding.

4. Coursera ( Coursera offers both free and paid cybersecurity courses from leading universities and organizations. While some courses require payment to access graded assignments and certificates, you can often audit the courses for free and gain access to the learning materials.

5. FutureLearn ( FutureLearn provides free cybersecurity courses from top universities and industry experts. Their courses cover topics like data security, online identity, and cybersecurity for small and medium-sized businesses.

6. SANS Cyber Aces Online ( SANS Cyber Aces Online offers free introductory courses in cybersecurity. They cover topics such as networking, operating systems, and system administration, providing a solid foundation for further cybersecurity learning.

7. YouTube: While not a dedicated learning platform, YouTube hosts a vast amount of cybersecurity content from industry experts and educators. You can find tutorials, lectures, and demonstrations on various cybersecurity topics, making it a valuable resource for self-paced learning.

Remember that while these platforms offer free courses, some of them also provide the option to upgrade to a paid version for additional features, such as certificates or graded assignments. However, the free courses on these platforms still provide valuable knowledge and skills in the field of cybersecurity.