For free.
For free.
We, at CK-12, believe every child on this planet should have equal access to great education.
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The latest from CK-12

Simulations, PLIX, and Adaptive Practice

We’re raising the bar with interactive learning activities and practice that adapts to individual student performance.



Teachers assign concepts to students and track their performance in CK-12 classes. Students can join their classes and receive assignments from their teacher.


Concept-based Learning.

Content is broken down and presented in multiple modalities to fit different learning styles.

CK-12 on all devices.

Access CK-12 on your desktop, tablet, or mobile phone.


Concept Collections

FlexBook® textbooks are deconstructed into bite-sized chunks of information.


Teacher Editions

FlexBook® textbooks are extended with workbooks, quizzes, and tests with corresponding answer keys.
Access CK-12 anytime and on-the-go.


FlexBook® Textbooks Launch

CK-12 launches fully customizable Math and Science textbooks that are free for the world to download or view online.


CK-12 was born

A small, yet talented group of people vow to make receiving a great education accessible to all.