Readability Checker
Find out whether your writing is easy to read. Paste your text to see six established readability scores, an average grade level with a plain-language verdict, reading time, and the longest sentences that would benefit from editing.
- Runs in your browser
- No sign-up
- Free to use
Readability
Scores appear here as you type. For reliable results, use at least 100 words.
Sentences to simplify
How to use Readability Checker
- Paste or type English text into the left box; 100 words or more gives reliable results.
- Read the average grade level and what it means for your audience.
- Compare the individual scores and the text statistics.
- Shorten the sentences listed under Sentences to simplify, then check again.
Readability Checker features
Six formulas
Flesch Reading Ease, Flesch–Kincaid Grade, Gunning Fog, SMOG, Coleman–Liau and the Automated Readability Index.
Average grade level
One summary number with a plain explanation of who can comfortably read the text.
Sentences to simplify
Lists the longest sentences with their word counts, so you know exactly where to edit.
Text statistics
Sentences, words per sentence, share of complex words, and reading and speaking time.
Live feedback
Scores update as you edit.
Private
Your text is analysed in your browser and never uploaded.
When to use Readability Checker
- Making web pages, help articles and emails easier to understand.
- Checking that patient information, policies and forms meet plain-language guidelines.
- Matching educational material to a year group.
- Editing marketing copy for clarity.
- Reviewing essays and reports before submission.
Readability Checker FAQ
What is a good readability score?
For a general audience aim for a Flesch Reading Ease of 60 or higher and a grade level of about 7 to 9. Many plain-language guidelines for public information recommend grade 8 or below.
Why do the formulas disagree?
Each measures different things: some count syllables, others letters or long words. Differences of a grade or two are normal, which is why the average is a useful summary.
Does it work for other languages?
No. The formulas and syllable counting are designed for English. A warning appears when the text does not look like English.
Does a good score mean good writing?
Not necessarily. The formulas measure sentence and word length, not logic, accuracy or structure. Use them as a signal, not a goal.
How do I improve my score?
Break long sentences in two, prefer short everyday words, use the active voice, and cut filler. The list of long sentences shows where to start.
What readability formulas measure
Readability formulas estimate how difficult a text is from two things that are easy to count: how long the sentences are and how long or complex the words are. Rudolf Flesch published his Reading Ease formula in 1948; it produces a score from 0 to 100, where higher is easier. The Flesch–Kincaid variant, developed for the US Navy in 1975, expresses the same idea as a school grade level.
Other formulas weigh the ingredients differently. Gunning Fog and SMOG focus on the share of words with three or more syllables, on the grounds that long words are usually less familiar. Coleman–Liau and the Automated Readability Index count letters instead of syllables, which made them easy to compute on early machines.
The scores correlate well with comprehension tests, which is why governments, health services and publishers use them in plain-language standards. They have limits, though. A text made of short sentences can still be confusing if it is poorly organised, and specialist readers may prefer precise technical terms over simpler but vaguer words.
The most reliable way to raise readability is to shorten sentences. Research on plain language suggests averaging 15 to 20 words, with variety in length. Editing the few longest sentences usually improves the scores more than any other change.