Quick Answer: HSK One offers free Chinese courses for every level. HSK 1 and HSK 2 are available now. HSK 3–9 are in development and will follow the same free, no-account model.
HSK 1 — Chinese Foundations: 12 lessons · 506 words · grammar · exercises · mock test · flashcards
HSK 2 — Everyday Chinese: 12 lessons · 750 words · grammar · exercises · mock test · flashcards
HSK 3 — Conversational Chinese: 12 lessons · 953 words · grammar · exercises · mock test · flashcards
HSK 4 — Fluent Chinese: 12 lessons · 972 words · grammar · exercises · mock test · flashcards
HSK 5 — Advanced Chinese: 12 lessons · 1059 words · grammar · exercises · mock test · flashcards
HSK 6 — Near-Native Chinese: 12 lessons · 1123 words · grammar · exercises · mock test · flashcards
HSK 7 — Academic Chinese I: 12 lessons · 2318 words · grammar · exercises · mock test · flashcards
HSK 8 — Academic Chinese II: 12 lessons · 1989 words · grammar · exercises · mock test · flashcards
HSK 9 — Mastery Chinese: 12 lessons · 1299 words · grammar · exercises · mock test · flashcards
HSK 3 (600 words) · HSK 4 (1,200 words) · HSK 5 (2,500 words) · HSK 6+ (5,000+ words)