CK-12 FlexBook 2.0 vs Oak National Academy

CK-12 FlexBook 2.0 provides customizable digital textbooks for K–12 subjects including science, math, and social studies. Lessons can combine text with PLIX interactives, simulations, adaptive practice, and related learning materials. Adaptive Practice draws questions from a library of more than 150,000 and adjusts selections based on student answers. Teachers can assign lessons, videos, interactives, and practice to whole classes or differentiated groups, then view progress reports. Educators can reorder chapters and edit or add content in customized FlexBooks. The service works in browsers on laptops, desktops, Chromebooks, tablets, and mobile devices, and is listed at free. Standalone Simulations and PLIX Interactives require a tablet-size screen or larger. Users may download PDFs of FlexBooks they create or customize, though interactive content may not render; CK-12-created PDFs are not downloadable. CK-12 says it is still converting all core content to FlexBook 2.0. Listed SSO or LMS partners include Google Classroom, Canvas, Schoology, Kiddom, Clever, and ClassLink.

Oak National Academy provides free curriculum plans and teaching resources for schools, teachers, trusts, and pupils. Its coverage runs through key stages 1–4 across 20 subjects and aligns with the national curriculum and exam boards. Materials include lesson plans, slide decks, quizzes, worksheets, and videos of teachers teaching the content. Oak presents them as adaptable starting points for different settings and pupils. Its AI tools help teachers and education professionals create, adapt, and enhance curriculum-aligned lessons, slides, and quizzes; pupils must not use these generative tools directly. The service is available on the web and through an open curriculum API. Content published after 1 September 2022 is generally available under the Open Government Licence v3.0, subject to exceptions and third-party rights. Earlier lesson videos cannot be downloaded, recorded, or reproduced under the stated licence. Oak says it has no paywalls, package tiers, or hidden costs, and provides child-focused privacy protections and a Help Centre.