Sources and licences

The HSK course is assembled from open word lists and sentence data plus this site's own lesson material.

• New HSK 3.x word lists: hsk3.1-syllabus (MIT), the 2025 syllabus lists for levels 1–6.
• Classic HSK 2.0 word lists: @nahanil/hsk-words (MIT). Definitions derive from CC-CEDICT (CC BY-SA 4.0).
• Example sentences, token glosses, grammar notes: hsk-sentences-audio by no7z (data CC BY-SA 4.0). Sentences are used with their translations unchanged; selection and ordering are ours.
• Lesson theory, dialogues and authored exercises (New HSK): the Daily lesson bank of this site.
• Stroke data: Hanzi Writer / Make Me a Hanzi (see the stroke order tool).
• Scheduling: FSRS-4.5 memory model with its published default parameters.