CK-12 FlexBook 2.0 vs zyBooks

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.

zyBooks is interactive digital courseware designed as an alternative to textbooks in STEM courses. Instructors can add custom content, create sections and chapters, and set course content and pacing. LMS integration is optional: zyBooks supports LTI 1.3 single sign-on and grade passback, with documentation for Canvas, Blackboard, Brightspace, and Moodle; activity scores can also be downloaded as CSV files. Security course materials include labs for practicing malware creation, network analysis, and vulnerability assessment. The maker describes accessibility against WCAG 2.2 A/AA, Revised Section 508, and EN 301 549, and offers accessibility modes and chapter PDFs. Access is by paid subscription, with a free evaluation available to instructors.