CK-12 Flexi
Free AI tutor built on open courseware
We don’t score or rank this tool. Our publisher also builds learning software in this area, so we give you the verified facts below and leave the judgement to you. You can run the Four Mismatches Test on it yourself.
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What it does
What the AI actually does — A GPT-4-class chat tutor grounded in CK-12's own curriculum library; on web, a Chrome extension, and WhatsApp.
Why it was built — Extend CK-12's free, open, curriculum-aligned resources into an always-on AI tutor that isn't paywalled.
Who built it
- Company
- CK-12 Foundation (non-profit)
- Founders
- Neeru Khosla · Murugan Pal
- HQ / origin
- Palo Alto, California, USA
- Founded
- Foundation 2007 (Flexi live by Dec 2023)
- Model
- B2C
- Languages
- English
- Pricing
- Free
We record durable facts only — no funding-raised or user-count figures. Unverified fields are marked [TBD] rather than guessed.
Where it sits
CK-12 Flexi is on the Learning Tools Index, in whole-curriculum ai tutors, built in United States.
Related & alternatives
- KhanmigoSocratic AI tutor across subjects, from Khan Academy
- Khan AcademyFree mastery-based courseware that Khanmigo sits on top of