Gaston Leroux · 1868
5–8 unknown words per 100 at CET-4 level. Looking each one up will stall you; this one wants glosses that appear in place.
Coverage = the share of words in the text you already know. The research gives two lines: 98% before independent fluent reading is realistic, 95% for the instructional level that needs support (Hu & Nation, 2000). Proper nouns are not counted as unknown — recognising that it is a name is enough; this book has 405 of them.
CET-6 and up, or read it with glosses. 84,690 words in total; at 150 words a minute for a non-native reader, about 9 h 25 min to finish. Average sentence length 12.9 words — short sentences, brisk pace. Reaching 95% coverage on this book (the floor for readability) takes roughly 16,000 word families.
The opening of The Phantom of the Opera, word for word. Tap any word you don't know and its meaning here appears beside it — no sign-up, tap as often as you like.
It was the evening on which MM. Debienne and Poligny, the managers of the Opera, were giving a last gala performance to mark their retirement. Suddenly the dressing-room of La Sorelli, one of the principal dancers, was invaded by half-a-dozen young ladies of the ballet, who had come up from the stage after "dancing" Polyeucte. They rushed in amid great confusion, some giving vent to forced and unnatural laughter, others to cries of terror. Sorelli, who wished to be alone for a moment to "run through" the speech which she was to make to the resigning managers, looked around angrily at the mad and tumultuous crowd. It was little Jammes--the girl with the tip-tilted nose, the forget-me-not eyes, the rose-red cheeks and the lily-white neck and shoulders--who gave the explanation in a trembling voice:
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The numbers above are computed, but we haven't cut The Phantom of the Opera into passages yet.
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These are already built, and closest in difficulty to The Phantom of the Opera.
Ordered by unknown words per 100. Lower reads easier; to step up a level, pick a higher number.
Computed by Readii from the public-domain text (updated 2026-10-21), not estimated by hand. The Readii reading level is our own scale, anchored on unknown-word density; it is not the same system as Lexile or AR and does not convert directly. Unknown words are measured against the CET-4 ∪ Gaokao lists, so this is difficulty for a Chinese-speaking learner, not a native-child reading level.