Robert Louis Stevenson · 1850
Heavy going at CET-4 level. Not unreadable — just not readable the look-every-word-up way.
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 79 of them.
Advanced — read it with glosses. 25,744 words in total; at 150 words a minute for a non-native reader, about 2 h 52 min to finish. Average sentence length 19.1 words. Reaching 95% coverage on this book (the floor for readability) takes roughly 18,500 word families.
The opening of The strange case of Dr. Jekyll and Mr. Hyde, 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.
Mr. Utterson the lawyer was a man of a rugged countenance, that was never lighted by a smile; cold, scanty and embarrassed in discourse; backward in sentiment; lean, long, dusty, dreary, and yet somehow lovable. At friendly meetings, and when the wine was to his taste, something eminently human beaconed from his eye; something indeed which never found its way into his talk, but which spoke not only in these silent symbols of the after-dinner face, but more often and loudly in the acts of his life. He was austere with himself; drank gin when he was alone, to mortify a taste for vintages; and though he enjoyed the theatre, had not crossed the doors of one for twenty years. But he had an approved tolerance for others; sometimes wondering, almost with envy, at the high pressure of spirits involved in their misdeeds; and in any extremity inclined to help rather than to reprove. “I incline to Cain’s heresy,” he used to say quaintly: “I let my brother go to the devil in his own way.” In this character, it was frequently his fortune to be the last reputable acquaintance and the last good influence in the lives of down-going men. And to such as these, so long as they came about his chambers, he never marked a shade of change in his demeanour.
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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.