Professional Materials
Texts + tasks from publisher-grade learning materials.
CEFR.AI calibrates language difficulty by combining text complexity with task demand.
We triangulate the CEFR.AI difficulty rating algorithm between placement outcomes on real learners, professional-grade text+task materials, and linguistic research on vocabulary/grammar/skills difficulty.
Texts + tasks from publisher-grade learning materials.
Real learner outcomes from texts + tasks in production.
GSE-aligned evidence on vocabulary, grammar, and skills.
Text analysis tools are meaningless without consideration of the demands of the reader. You could have a difficult text, but all that is required of the user is to identify the topic. That is why CEFR.AI is the first open-source research into language level difficulty based on real-world use of language. Find out more on our Research page.
Scoring logic, assumptions, and calibration strategy are designed to be inspectable and reproducible.
CEFR.AI is the core layer. Products can run as first-party apps or external tools powered by CEFR.AI.