The 95% and 98% rule
How hard a text feels depends mostly on how many of its words you do not know. Studies of second-language readers found that adequate comprehension starts when a reader knows about 95% of the running words, one unknown word in every 20, and that reading becomes comfortable and enjoyable at about 98%, one unknown word in every 50 (Hu & Nation, 2000; Laufer & Ravenhorst-Kalovski, 2010).
The checker estimates that share for you: words at or below your level count as known, words above your level as probably unknown.
| Known words | Verdict | Best use |
|---|---|---|
| 98% or more | Comfortable | Reading for pleasure and fluency. Pick these for extensive reading. |
| 95–98% | Challenging | Learning new words in context. Read with a tap-to-translate tool. |
| Under 95% | Too hard | Study material, not reading practice. Pre-learn key words or choose an easier text. |
How difficulty is measured
- Vocabulary difficulty looks at the share of words above B1. Low means almost all words are everyday words; high means many advanced or rare words.
- Sentence complexity is based on the average sentence length: under 12 words is low, 12–20 medium, over 20 high.
- Reading ease is the Flesch Reading Ease score, from 0 (very hard) to 100 (very easy). It measures sentence and word length, not vocabulary, so it is shown for reference.
- Estimated CEFR level combines vocabulary and sentence length, as in the CEFR text level checker.
Comfortable or challenging: which should you choose?
Both have a place. Extensive reading, reading a lot of comfortable text, builds speed and fluency and lets you meet known words again and again until they are automatic. Intensive reading of challenging text is where you meet most new words.
A good routine mixes the two: most of your reading time with comfortable books, plus shorter sessions with challenging texts where you look up and save new words. Graded books are an easy way to stay in the comfortable zone; you will find free English books for every level on Okuzeka.
How to read a text that is too hard
- Learn the key words first. The list under your result shows the words above your level, most frequent first.
- Read the text once for the general idea without stopping, then a second time for detail.
- Look up only the words that block your understanding, and look them up in context. A dictionary entry with ten meanings is slower and less helpful than the meaning in your sentence.
- Save the words you want to remember, with the sentence, and review them over the next days.
The Okuzeka reader does steps 3 and 4 for you: tap a word to see its meaning in that sentence, in your language, and save it as a flashcard.
Checking whole books
To check a book, paste two or three pages from different chapters rather than only the first page; openings are often harder or easier than the rest. If the result is challenging for you, the book is a good choice for reading with help. For a quick start, browse B1, B2 and C1 English books on Okuzeka, which are already sorted by level.
