What is CK-12 Foundation?
CK-12 is an interactive and intelligent learning platform that's free for everyone.
Used by more than 200 million students and teachers worldwide, CK-12 empowers learners with high-quality content and cutting-edge technology.
FlexBooks® 2.0 technology enables students to learn in their own way - whether by reading, watching videos, exploring interactive simulations, or answering personalized practice questions with immediate feedback for both correct and incorrect answers.
Flexi the AI-powered tutor makes learning engaging and answers students’ science questions with interactive examples to help them understand the underlying concepts (coming soon for math). Flexi provides students with timely reminders of upcoming assignments, topics they may have forgotten or missed, their next topic to learn, and any unfinished work - helping them stay on track. Flexi helps students self-reflect to answer questions like: "How am I doing?", "How can I improve?", "What am I missing?"
Flexi empowers educators as well, providing every teacher with a digital assistant that uncovers student learning gaps and misconceptions, and offers personalized insights on where to intervene effectively. Flexi updates the grade book in your LMS as students turn in their work so that you can focus on teaching, and even helps assign auto-graded assignments to classes in Google Classroom, Schoology, and Canvas
Educational Impact
 Company | Business Name: CK-12 Foundation HQ Location: United States Founded: 2007 |
| Age Range | 5-7, 8-10, 11-13, 14-16, 17-18, 19+ |
 Features | Test PrepAssignmentsDigital TutorDashboardInstant FeedbackTeacher AssistantLms IntegrationPracticeStudy Help |
 Languages | Arabic, Chinese, English, French, German, Italian, Japanese, Korean, Spanish |
 Accessibility | Moderate features |
 Policies |  Terms of ServicePrivacy Policy |
 Requirements | Internet - Low BandwidthInternet - High BandwidthDesktop - MacDesktop - WindowsDesktop - ChromebookMobile - iPhoneMobile - iPadMobile - WindowsMobile - Android As long as you have a phone or laptop that can access the internet, you can use CK-12! |
 Set Up | Class roster can be uploaded, but individual users only need basic information. It takes about one minute. |
 Training | Webinars Our platform is designed to be simple and intuitive - you can use it without any training. However, to help you get the most out of CK-12, we also host live webinars, provide on-demand webinars, and run a free certification program. |
 Support | EmailFAQs/Forum |
| Home Learning | Parent Access Anyone can create the account. |
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CK-12 Foundation PricingPricing Plans Free Version CK-12 has no subscription, no advertising and no licensing to schools or users. Everything on CK-12 is 100% free – forever. Get in touch if you wish to make a donation.  Optimised for a quick response | |
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CK-12 Foundation Reviews
from 33 Verified Reviews
User rating
Country
Fatime
English teacher
Used CK-12 Foundation for 0–3months
Jan 2021
Every thing is clearly good
Fatime found CK-12 Foundation:
- Significantly improves attainment“Yo explain to my students everything in the poin of view like they want”
- Significantly builds student knowledge“They are able to express everything”
- Slightly improves teaching efficiency and productivity
- Significantly reduces teacher workload
Dec 2020
CK-12 saves time and work for the teacher, provides the lessons in "bite-sized" chunks, is offered in several different languages, and appeals to students. The practice at the end of each section is invaluable.
Connie found CK-12 Foundation:
- Significantly improves attainment“They offer practice problems for each section, with automatic feedback to the students. Students continue until they have answered 10 questions correctly, or until they have reached the level of proficiency that they desire.”
- Significantly builds student knowledge“See previous answer.”
- Significantly improves teaching efficiency and productivity“Having automatic grading that is synced directly into Google Classroom.”
- Significantly reduces teacher workload“see above”
Nancy Linsangan
Earth Science Teacher
Used CK-12 Foundation for 4-6 months
Dec 2020
CK12 is amazing. Factual, concise and interactive -- what else could a Science teacher ask for!?!
Nancy Linsangan found CK-12 Foundation:
- Significantly improves attainment“My students have been able to acquire or attain information and understanding, of class topics, from the CK12 online flexbooks.”
- Significantly builds student knowledge“Higher test scores”
- Significantly improves teaching efficiency and productivity“I am able to assign work right from the CK12 application.”
- Slightly reduces teacher workload“I can assign work from the CK12 application, but not from my school's LMS, Schoology. I have been waiting for a few weeks for a "secret key" (?).”
Dec 2020
i have told everyone i can
Gina D'Aquila found CK-12 Foundation:
- Significantly improves attainment“students love it”
- Significantly builds student knowledge“lessons and videos”
- Significantly improves teaching efficiency and productivity“help to keep continuity”
- Significantly reduces teacher workload“dont have to search for hours to find material”
- Significantly saves school money“free- hopefully stays that way”
Dec 2020
I love the integrated simulations and videos in the CK12 chapters. It's an interactive textbook. I wish I had this when I was growing up.
Sara Turner found CK-12 Foundation:
- Moderately improves attainment“Full access online to updated content.”
- Moderately builds student knowledge“I love the explore more option. I'm not sure if my students are actually using it, but it's there for them.”
- Moderately improves teaching efficiency and productivity“CK12 is integrated into Canvas which has helped tremendously with grading efficiency.”
- Moderately reduces teacher workload“Again, full integration into Canvas has helped to reduce teacher workload with grading.”
- Significantly saves school money“Free program means more funding for other avenues. However, our textbooks were so extremely outdated that I'm not sure any money has been spent in that direction for a long time.”
Lisa Stritzel
teacher assistant w/substitute teacher license
Used CK-12 Foundation for 4-6 months
Dec 2020
I feel like ck12 is a great addition to teacher. In helping the students learn in a fun way as well educational way.
Lisa Stritzel found CK-12 Foundation:
- Significantly improves attainment“The kids feel like they are more engaged.”
- Significantly builds student knowledge“They have improved their understanding content in varies subjects.”
- Significantly improves teaching efficiency and productivity“The examples of the simulations and plix have helped with the teaching process in the classroom.”
- Moderately reduces teacher workload“Do not have to individual go in and put in a grade. Which is nice.”
- Slightly saves school money“No examples at this time on how school money is impacted.”
Dec 2020
Nice produce... AND FREE
Dr. David Block found CK-12 Foundation:
- Significantly improves attainment“nope”
- Significantly builds student knowledge“the content and adaptive practice”
- Significantly improves teaching efficiency and productivity“It's a well rounded product with reports on my students”
- Significantly reduces teacher workload“See previous”
- Slightly saves school money“Once I convince them to stop buying textbooks, it will save”
Jacob Kramer
High School Science Teacher
Used CK-12 Foundation for 0–3 months
Dec 2020
I have greatly enjoyed using CK-12 in my Biology classroom. The website is user-friendly, is a great way for students to review material at their grade level, and offers fantastic formal and informal assessment opportunities.
Jacob Kramer found CK-12 Foundation:
- Moderately improves attainment“Students have additional practice with the material to strengthen their understanding of the material.”
- Significantly builds student knowledge“Students can read lessons on concepts that they may struggle with at their own pace to gain a deeper understanding of the material. The adaptive practice is also a great way for students to test their knowledge and let them know if they need additional practice with the material.”
- Significantly improves teaching efficiency and productivity“My school is currently on a hybrid model and CK-12 has been a great resource for the students on their days away from school. The material is still challenging for the students and a great way to strengthen their understanding of material we discussed in class or introduce them to concepts that we are going to discuss the next day they are in school.”
- Significantly reduces teacher workload“The class reports feature is a great way to assess students' performance on a variety of assignments at a mere glance. The website is user-friendly for both myself and my students.”
- Significantly saves school money“In the near future, I can see myself using CK-12 as a free virtual textbook for my Biology classes.”
Shon Holland
Middle school science lead
Used CK-12 Foundation for 5 years+
Dec 2020
It’s an amazing resource that is engaging and gets straight to the point of what students need to know
Shon Holland found CK-12 Foundation:
- Moderately improves attainment“The interactive pieces that directly support what students have just read.”
- Significantly builds student knowledge“They see a direct connection between the text, videos, and simulations to the real world.”
- Moderately improves teaching efficiency and productivity“There aren’t 100 different sites to visit - it’s all self contained”
- Significantly reduces teacher workload“Consistent layout, simple directions allow us to answer questions based on content and not on “where to find things””
- Significantly saves school money“Ck12 is free which allowed us to test it with no worry about “waisting money””
Dec 2020
It is user friendly and yet it is engaging and employs lots of different activities as well as alignment for NGSS
Jennifer found CK-12 Foundation:
- Moderately improves attainment“Students had to keep taking the practice till they get 10 so it helps them see what is important and what they need to be getting from the assignments”
- Moderately builds student knowledge“The simulations help them actively participate”
- Moderately improves teaching efficiency and productivity“Students can use the CK12 without a teacher”
- Moderately reduces teacher workload“CK 12 has lots in one spot”
- Significantly saves school money“I have not had to ask my school for money”
Chriss O
Science Teacher
Used CK-12 Foundation for 4-6 months
Dec 2020
The materials that CK-12 supplies, FOR FREE!!!, are amazing. We are using it for Biology, Chemistry, Physical Science, Physics, Astronomy, and Zoology classes.
Chriss O found CK-12 Foundation:
- Significantly improves attainment
- Significantly builds student knowledge
- Significantly improves teaching efficiency and productivity“As this is my first year teaching remotely, there is no way I could develop the quality of content that is found in their platform.”
- Significantly reduces teacher workload“I love that they provide short discreet lessons so that I can easily pick which ones match my curriculum the most. I have a CK-12 lesson for just about every topic that I need.”
- Significantly saves school money“Our science department was supposed to get new textbooks this year but we did not due to the pandemic. Some of our books are close to 20 years old. CK-12 is definitely saving our district money and helping the teachers teach with up-to-date materials.”
Dec 2020
I'm still getting to know the platform. It has a lot of promise and I'm excited to learn more, but I'm not going to push a platform unless I really believe in it and understand it.
Jaclyn found CK-12 Foundation:
- Slightly improves attainment
- Slightly builds student knowledge
- Moderately improves teaching efficiency and productivity“I like the integration with google classroom.”
- Moderately reduces teacher workload“The grading from the practice questions is very helpful and I love the score reports for each student.”
- Slightly saves school money“If I converted to flexbooks, I wouldn't need textbooks, but at this time we don't use ck-12 exclusively. I still need to review the flexbook to see if it is the right tool for me.”
Raylene Olinger
HS Science teacher
Used CK-12 Foundation for 4-6 months
Dec 2020
I think the resources are great.
Raylene Olinger found CK-12 Foundation:
- Moderately improves attainment“Highly engaging to students”
- Moderately builds student knowledge“Focused lessons”
- Moderately improves teaching efficiency and productivity“All materials in one place, easy to use with Google Classroom”
- Moderately reduces teacher workload“Ease of use with Google Classroom”
- Moderately saves school money“This resource being free has been a blessing”
Dec 2020
Well, 10 means I'm very likely to recommend it to someone else.
Brooke found CK-12 Foundation:
- Slightly improves attainment
- Significantly builds student knowledge
- Significantly improves teaching efficiency and productivity“The adaptive practice is personalized to the student and the data is easily accessible so I don't have to spend so much time grading or reinforcing individual students.”
- Significantly reduces teacher workload“See last comment.”
- Significantly saves school money“It's free...”
Dec 2020
Knowledge base grows horrizantally and vertically
Nagaraja found CK-12 Foundation:
- Moderately improves attainment“Recent YouTube creation”
- Moderately builds student knowledge“On DNA”
- Significantly improves teaching efficiency and productivity“STEM content”
- Does not reduce teacher workload“More work and notes making”
- Slightly saves school money“Not in touch with schools”
Dec 2020
I have told other homeschool parents to use it.
Greg found CK-12 Foundation:
- Moderately improves attainment
- Significantly builds student knowledge
- Significantly improves teaching efficiency and productivity“I can look at the assignments before my student completes them and keep up in my copy of the book just like regular books but I can have them on any device anytime.”
- Significantly reduces teacher workload“I just let my student go through the work and check after.”
- Moderately saves school money“I use it for History and Science and it's free. I would be paying for those in another program. The books are free and very well done.”
Dec 2020
Students enjoy using it because it's a combination of reading and video
Diane found CK-12 Foundation:
- Slightly improves attainment“It's difficult to determine attainment because there is no check-for-understanding. quiz or questions.”
- Slightly builds student knowledge“The "A" students would do the work and retain the knowledge but the "C" and "B" students didn't”
- Slightly improves teaching efficiency and productivity“It”
- Slightly reduces teacher workload“I could not figure out how to verify that students finished their assignments with correct answers”
- Moderately saves school money“My school is paying $80k for a different virtual curriculum that is challenging for my middle school students. They like CK12 better!”
Thomas Freeman
Science + Technology Teacher
Used CK-12 Foundation for 1-2 years
Dec 2020
CK-12 has the potential to become the most widely-utilized digital textbook and science resource of the future. An open education environment that could rival Wikipedia in popularity.
Thomas Freeman found CK-12 Foundation:
- Significantly improves attainment“Students can use the material to review topics, use it as a textbook, and get more engaged using the simulations and PLIX.”
- Significantly builds student knowledge“Students get a chance to learn new vocabulary and work towards mastery of a topic.”
- Significantly improves teaching efficiency and productivity“CK-12 makes assigning mastery-based homework easy and makes it easy to access free learning resources anywhere.”
- Significantly reduces teacher workload“The self grading mastery-based assignments make it easy for students to practice frequently and often without increasing the amount of manual grading.”
- Significantly saves school money“All the resources are free online.”
Dec 2020
very interesting, just not totally fits the lebanese cucrriculum
Daniel found CK-12 Foundation:
- Moderately improves attainment“real world, simulation”
- Moderately builds student knowledge“rotation”
- Significantly improves teaching efficiency and productivity“imbede quiz”
- Slightly reduces teacher workload
- Does not save school money
Casey Hackman
6th grade teacher
Used CK-12 Foundation for 7–12 months
Dec 2020
With CK-12 being FREE and readily available, I am telling many about the resource.
Casey Hackman found CK-12 Foundation:
- Moderately improves attainment
- Significantly builds student knowledge
- Significantly improves teaching efficiency and productivity“When I want students to grapple with a concept, CK-12 has already done the research for a particular topic.”
- Significantly reduces teacher workload“I can easily pull up a chapter and it supplements what I am currently teaching.”
- Significantly saves school money
Brenda Graminski
Science Teacher
Used CK-12 Foundation for 7–12 months
Dec 2020
Brenda Graminski found CK-12 Foundation:
- Significantly improves attainment“Can be used on any device so more equal access”
- Moderately builds student knowledge“The adaptive practice, and engagement with text.”
- Significantly improves teaching efficiency and productivity“Scoring adaptive practice, quantifying engagement and grading quizzes.”
- Moderately reduces teacher workload
- Moderately saves school money“It's a free resource and easily accessible.”
Mohammed Ali Al Jaf
Physics Teacher & Supervisor
Used CK-12 Foundation for 0–3 months
Dec 2020
I can't tell now.
Mohammed Ali Al Jaf found CK-12 Foundation:
- Slightly improves attainment“This is my first to join this masterclass”
- Slightly builds student knowledge“I haven't attended any masterclass yet.”
- Slightly improves teaching efficiency and productivity“I can't tell for sure.”
- Slightly reduces teacher workload“I think so.”
- Slightly saves school money“I can tell in the future.”
Dec 2020
Since we went virtual and I teach E-learners full time, CK12 has been a Godsend. Students like the short, accessible lessons, and I like how I can spend time helping them instead of preparing online content
James Byrne found CK-12 Foundation:
- Significantly improves attainment“Students are in control of their learning”
- Moderately builds student knowledge“Some students start to ask better questions”
- Significantly improves teaching efficiency and productivity“I can spend less time planning online curriculum and more time assisting learners.”
- Significantly reduces teacher workload“I can get a great report on how engaged students are and how well they understand the material”
- Does not save school money
Crystal
middle school science and STEM teacher
Used CK-12 Foundation for 5 years+
Dec 2020
CK-12 has been my "go-to" for over 5 years and it has only gotten better. Science content delivery has changed tremendously and I believe that CK-12 has the best model for delivery for today's science student.
Crystal found CK-12 Foundation:
- Moderately improves attainment“not now”
- Moderately builds student knowledge“students use adaptive practice and simulations in addition to reading”
- Moderately improves teaching efficiency and productivity“I use a hybrid teaching model and CK-12 has many useful options for me”
- Moderately reduces teacher workload“adaptive practice works really well to help differentiate for students”
- Slightly saves school money
Dec 2020
You’re excellent and I wish you could make all resources free to teachers worldwide.
Lizelle found CK-12 Foundation:
- Significantly improves attainment“Test scores improve”
- Significantly builds student knowledge“Better understanding of concepts”
- Significantly improves teaching efficiency and productivity“Good demos and exercises”
- Significantly reduces teacher workload“Having good demos like CK12 available online, reduces stress and research time for teachers”
- Moderately saves school money“I can’t really speak to that as I have only been able to use free resources from ck12”
