CK-12 Flexbooks


CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. As a leading member of the OER movement, CK-12 is using an open-content, web-based collaborative model termed the "FlexBook." With these free, common core aligned and NSES aligned digital textbooks, CK-12 intends to pioneer the generation and distribution of high quality educational STEM content that will serve both as core text as well as provide an adaptive environment for learning through the FlexBook Platform™.

The content generated by CK-12 and the CK-12 community will serve both as source material for a student's learning and provide an adaptive environment that scaffolds the learner's journey as he or she masters a standards-based body of knowledge, while allowing for passion-based learning.

Key Benefits

  • Access to free textbooks
  • High quality educational content created by educators
  • Content customized to reflect "today" and the different needs of students
  • Quality ensured by CK-12's Community of Educational Practitioners
  • Increased pedagogic choice for all teachers, aligned to state standards as well as developmentally correct content
  • Supported by publishing tools that facilitate quick and easy content creation and distribution
  • Collaborative learning via a community where authors, teachers, and students create, access, share, rate, recommend, and publish

Initially, CK-12 has commissioned a baseline archive of open educational resources (textbooks) through a combination of author donations, licensing partnerships, incentives for community-based authorship, and university collaborations. Flowing from this baseline, CK-12 will actively moderate the expansion of its content base from an active, contributing community while creating a framework for aligning its assets with an expanding base of learning standards like McREL Compendium. CK-12 intends to make use of the Creative Commons Attribution-Share Alike license, which grants freedom to anyone to use and reuse its core materials. For print versions, the organization envisions working with a marketplace of on-demand presses to provide customized, but traditional looking, paper textbooks at low cost. This cost will be born by the user at their discretion directly at the on-demand press.

CK-12 is presently comprised of a group of visionary advisors and highly accomplished Silicon Valley engineers. In addition to possessing deep skills in emerging web technologies, CK-12's technical organization is uniquely capable of delivering a high performance, scalable infrastructure that will be accessible to all students, teachers, and parents anywhere in the world. In addition to the technical team, CK-12 has seeded content through experienced and practitioner developers of K-12 content. While the initial set comprises sixteen traditional but modularized textbooks, the set is expected to grow rapidly.

Next Generation Textbooks

CK-12 allows one to customize and produce content by re-purposing to suit what needs to be taught, using different modules that may suit a learner's learning style, region, language, or level of skill, while adhering to the local education standards.

Flexibility + Textbook = FlexBook.

The Need

Today, textbooks in use in the K-12 system are limiting, expensive, and difficult to update. Because of this, K-12 teachers find it hard to cater to different needs as well as to introduce new concepts.

We need a more flexible and less expensive system to create and distribute books and online content. The K-12 system needs to be provided with access to high quality online content, and simple solutions to create, customize, update, and print. This new concept provides a system that will follow an open educational resource philosophy to place content online that can be "mixed, modified, and printed" to suit a teacher's need while adhering to curriculum standards. Our solutions will enable all students to access and obtain an education around the globe.


Plan Price Details
CK-12 Flexbooks Free Free education resources. Standards-aligned and customizable.


September 2, 2015

CK-12 is a great app for both teachers and educators. It can help students stay engaged and interested, and provide teachers with the tools they need to be effective. With everything online, it is streamlined and efficient.

August 31, 2012

This site a free online flexible textbook for various subjects. The textbooks are aligned with the curriculum standards of various states. The content of the textbooks can be moved around in order to meet the needs of the teacher.