text tool
Readability checker
Paste your text to get its Flesch Reading Ease score, its Flesch-Kincaid grade level and its average sentence length, with every long sentence and passive phrase marked where it sits. The five hardest sentences are listed, and pressing one selects it in the box so you can rewrite it there.
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- Runs on your device, nothing is uploaded
- Free, no sign in
- No watermark, no file limit
How it works
- 1
Paste your text
Put it in the Your text box. The five score cards and the scale fill in as you type.
- 2
Read the scores
Reading ease runs from 0 to 100, where 60 and above is plain English. Grade level is the US school year a reader needs.
- 3
Set what counts as long
Choose 20, 25, 30 or 35 words. Sentences over the limit turn amber in the marked copy, and passive phrases get a violet underline.
- 4
Fix the hardest sentences first
Press a sentence under Hardest sentences to select it in the box, rewrite it, and watch the scores move. Copy the scores keeps a record.
What the two Flesch numbers measure
Both formulas use only two things: how many words a sentence has on average, and how many syllables a word has on average. Reading Ease is 206.835, minus 1.015 times the words per sentence, minus 84.6 times the syllables per word. It runs from about 0 to 100, and higher is easier; 60 to 70 is plain English that most adults read comfortably. The Flesch-Kincaid grade turns the same two inputs into a US school grade: 0.39 times words per sentence, plus 11.8 times syllables per word, minus 15.59. It was derived in 1975 for the US Navy, which needed to match training manuals to the reading level of enlisted personnel.
Sentence length is the number you can fix fastest
Long words are often unavoidable: a medical form has to say medication, and a lease has to say landlord. Sentence length is almost always a choice. Government style guides converge on the same figures: the Australian Government Style Manual asks for an average of 15 words and no more than 25, and GOV.UK asks writers to check any sentence over 25 words. That is why 25 is the default limit here. Splitting one 40 word sentence into two can move the Reading Ease score as much as rewriting several long words, and it is usually the easier edit.
Passive voice hides who has to act
A passive sentence puts the action before, or without, the person doing it: the form must be submitted by Friday, rather than you must submit the form by Friday. Readers then have to work out whether they are the one who acts. The checker lists every phrase where a form of to be meets a past participle, so you can decide case by case. Passive voice is not always wrong; it suits sentences where the actor is unknown or unimportant. The aim is to make each one a choice.
Readable questions get better answers
Forms and surveys are where readability pays most directly. A respondent who has to read a question twice either guesses or leaves, and both show up in the data. Short questions with one idea each are easier to answer the same way twice, which is what makes answers comparable. Run the question list through the checker before publishing: aim for a Reading Ease above 60, and split any question the checker marks as long, since it is very likely asking two things at once.
Limits worth knowing
Readability formulas measure the surface of the text, not its meaning. A string of short, common words can still be confusing, and a precise technical sentence can score poorly while being exactly right for its readers. Treat the score as a prompt to look, not a verdict. Different tools also count syllables and split sentences differently, so expect a few points of disagreement between them. Nothing is uploaded and nothing is stored, ever.
Limits
- The syllable counter is English-only and approximate on names and jargon. It counts vowel groups rather than looking words up, so a name such as Siobhan or a term such as GIF can be off by a syllable.
- Text that is mostly Chinese, Japanese or Korean gets no Flesch scores, because the formulas count English syllables.
- Under 100 words, scores swing a lot with each sentence, and the page says so.
- Passive voice is found by pattern, a form of to be followed by a past participle, so a few matches will be wrong in each direction.
- One unbroken paragraph of tens of thousands of words takes several seconds to score. The page stays usable while it works, and text split into paragraphs scores in a fraction of a second.
What it does not do
- It does not rewrite anything. It shows where to look and leaves the wording to you.
- It does not check spelling or grammar.
- It does not score other languages correctly, even ones written in the Latin alphabet such as Spanish or German.
- It does not upload or store your text.
Questions people ask
What is a good Flesch Reading Ease score?
For anything the public reads, such as a form, a notice or a web page, aim for 60 or higher, which is plain English. Customer letters often land between 60 and 70. Contracts and academic writing often score 30 to 50, which a specialist reader can manage but a general reader finds hard. A score above 80 is very easy and suits instructions and children's material.
Why do different readability checkers give different scores for the same text?
The formulas are fixed, but the counting is not. Tools disagree about how many syllables a word has, whether a heading or a list item is a sentence, and how abbreviations such as Dr. or e.g. split sentences. One extra sentence break changes the average sentence length, which moves every score. Compare drafts in the same tool rather than comparing numbers across tools.
Does the grade level mean a reader needs that much schooling?
It is a rough guide based on US school grades, not a test of any one reader. A grade of 8 means a typical 13 or 14 year old in the US could follow the text. Adults read below their highest level of schooling when tired, rushed or reading in a second language, so writing for the public a few grades lower than you think is safer.
Can I check readability for a language other than English?
Not reliably here. The Flesch formulas were fitted to English, and the syllable counter follows English spelling rules, so Spanish, German or French text gets a number that does not mean what it says. Other languages have their own adapted formulas with different constants. Text that is mostly Chinese, Japanese or Korean is detected and gets no score at all.
Should every sentence be short?
No. A page of identical short sentences reads like a list and loses the links between ideas. The guidance is about the average and the outliers: keep the average near 15 words and look hard at anything over 25. Mixing a few longer sentences that carry a connected idea with shorter ones that land a point is what makes text both easy and pleasant to read.
Turn the clear wording into a form
Take what you made here into forms.
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Background reading: the question page on this.
Written and checked by the OneCraft team. Last checked .