What the Flesch Reading Ease score is
The Flesch Reading Ease score estimates how easy a passage is to read using two things: average sentence length and average syllables per word. Shorter sentences and shorter words push the score up. The formula is 206.835 minus 1.015 times the words per sentence, minus 84.6 times the syllables per word. Higher means easier.
A companion measure, the Flesch-Kincaid grade level, converts the same inputs into an approximate school grade in the US system. A result around 8, for instance, suggests the text is readable by an average student in that grade.
These are formulas, not judgments. They do not measure whether the ideas are clear, whether the vocabulary suits your audience, or whether the writing is good. A passage full of short sentences can score as easy while still being confusing. They are rough indicators of surface complexity only, and they are not a search ranking factor.
Why readability is worth checking
Plain, direct writing helps most readers, including experts who are skimming. If you write help pages, product copy, instructions or articles for a general audience, a quick check can show when sentences have grown too long or when jargon is stacking up.
It is useful when editing: run a draft, shorten the longest sentences, swap a few long words for simpler ones, and see how the score moves. Comparing two versions of a paragraph makes the effect concrete.
Be careful with technical or specialist material. Terms that readers know well may count as many syllables, which lowers the score even when the text is perfectly clear to its audience. Treat the number as a prompt to re-read, not a pass or fail grade.
How to use the Readability Checker
- Paste or type your text into the box. A short sample is already there.
- Read the four figures: Words, Sentences, Words/sentence and Grade level.
- Check the large score and its label below, shown as a Flesch Reading Ease value with a plain description.
- Edit the text and watch the values update as you type.
The labels are: 80 and above is "Very easy to read", 60 to 79 is "Easy to read", 40 to 59 is "Fairly difficult", and anything below 40 is "Difficult". For a plain length check, use the Word Count Tool.
Accuracy and limits
Sentences are found by splitting on periods, exclamation marks and question marks, so abbreviations such as "e.g." or decimal numbers can be counted as extra sentence breaks, and text without punctuation may be treated as one long sentence. Lists and headings with no end punctuation are the same problem.
Syllables are estimated by counting groups of vowels in each word and subtracting one for a trailing "e". This is a rough rule that suits plain English but misjudges some words. The score is clamped between 0 and 100 on the display, and the grade level cannot go below 0.
The formulas were designed for English prose, so results for other languages are not reliable. Use the figures as guidance, and always read your text aloud as a final check. The analysis happens in your browser, and your text is not uploaded.