F. Scott Fitzgerald · 1925
About one unknown word every twelve at a 5,000-word vocabulary. Readable, but it wants support — and that band is also where readers most easily fall into flow.
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 468 of them.
Comfortable from about 8,000 words, or read it with glosses. 48,443 words in total; at 150 words a minute for a non-native reader, about 5 h 23 min to finish. Average sentence length 13.7 words. Reaching 95% coverage on this book (the floor for readability) takes roughly 10,000 word families.
The opening of The Great Gatsby, 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.
In my younger and more vulnerable years my father gave me some advice that I’ve been turning over in my mind ever since.
“Whenever you feel like criticizing anyone,” he told me, “just remember that all the people in this world haven’t had the advantages that you’ve had.”
He didn’t say any more, but we’ve always been unusually communicative in a reserved way, and I understood that he meant a great deal more than that. In consequence, I’m inclined to reserve all judgements, a habit that has opened up many curious natures to me and also made me the victim of not a few veteran bores.
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Readii cuts this book into three-minute passages. Tap a word you don't know and its meaning in that exact sentence appears in place — no jumping out, no losing the thread.
The opening chapters are free — no account, no card.
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 counted against a frequency list built from a large subtitle corpus, so the bands mean the same thing for any learner of English, whatever your first language. This is difficulty for a non-native reader, not a native-child reading level.