CK-12 FlexBook 2.0 vs Saylor 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.

Saylor University offers self-paced online courses, skill development programs, and graduate degrees. Its catalog lists 164 free courses spanning professional skills and college-level subjects. Materials are curated from free and open online resources by expert educators, and learners can earn free digital certificates by passing course exams. Some courses have ACE credit recommendations, but earning credit requires a proctored credit exam; optional proctoring costs $5 USD per exam session. The organization serves people pursuing personal or professional development, college credit, and graduate degrees. Learners can access courses on the web or use the Saylor University or Moodle mobile app on iOS and Android. Some activities can be downloaded for offline use, though some site features and settings are unavailable in the apps. Sign-in supports Google, Facebook, LinkedIn, and Microsoft. Saylor says it collects account and usage information and does not sell personal information. Its privacy policy describes administrative, physical, and technical safeguards while noting that absolute security cannot be guaranteed. Saylor University is the primary initiative of the Constitution Foundation, a nonprofit founded by Michael J. Saylor.