Website: https://www.oercommons.org/

Best For: All learners—primary, secondary, collegiate, career/upskill, homeschool.

Cost: Completely free.

Notes: Provides free access to a vast library of open educational resources.

Website: https://open.umn.edu/opentextbooks/

Best For: Collegiate, career/upskill.

Cost: Completely free.

Notes: All textbooks are openly licensed and free to download.

Website: https://www.ck12.org/

Best For: Primary, secondary, homeschool.

Cost: Completely free.

Notes: Provides customizable, standards-aligned content.

Website: https://www.merlot.org/

Best For: Secondary, collegiate, career/upskill.

Cost: Completely free.

Notes: Offers peer-reviewed educational materials at no cost.

Website: https://ocw.mit.edu/

Best For: Collegiate, advanced secondary students, career/upskill.

Cost: Completely free.

Notes: Free access to course materials from MIT.

Website: https://www.curriki.org/

Best For: Primary, secondary, homeschool.

Cost: Completely free.

Notes: Free resources for K-12 education.

Website: https://openstax.org/

Best For: Secondary (AP courses), collegiate.

Cost: Free access to textbooks.

Notes: Physical copies can be purchased at a low cost; digital versions are free.

Website: https://www.khanacademy.org/

Best For: Primary, secondary, collegiate, homeschool.

Cost: Completely free.

Notes: Offers free lessons and practice exercises across various subjects.

Website: https://www.hippocampus.org/

Best For: Secondary, collegiate.

Cost: Completely free.

Notes: Free multimedia content in general education subjects.