The numbers first: the HSK 3.0 standard defines roughly 11,000 words across its nine bands, with about 5,400 in bands 1–6 alone — while the entire old HSK 2.0 range topped out around 5,000. Someone targeting "HSK 4" today faces meaningfully more language than someone who took it a year ago. Copying each character ten times into a notebook was already slow; at this scale it simply does not work. Here is a three-layer system that does.
Layer 1 — Filter: study only what is inside your band
The most common failure mode when a word list doubles is drifting into "interesting words from the internet". The 3.0 standard publishes vocabulary per band, which means you can draw a precise border around what your exam actually tests: