A readability checker scores how easy your text is to read using formulas like Flesch Reading Ease and Flesch-Kincaid Grade Level, which are based on sentence length and word length. Paste your copy into the QCK Readability Checker to get both scores and see which sentences to shorten, then edit until the text reads clearly for your audience.
What readability scores measure
Readability formulas estimate difficulty from two things a computer can count: how many words are in each sentence, and how many syllables are in each word. Longer sentences and longer words produce harder scores.
Flesch Reading Ease
The formula is:
206.835 - 1.015 x (words / sentences) - 84.6 x (syllables / words)
Scores usually fall between 0 and 100. Higher is easier. As a rough guide:
| Score | Difficulty |
|---|---|
| 90 to 100 | Very easy |
| 70 to 80 | Fairly easy |
| 60 to 70 | Plain English |
| 50 to 60 | Fairly difficult |
| 30 to 50 | Difficult |
| 0 to 30 | Very difficult |
Flesch-Kincaid Grade Level
This variant converts the same inputs into a US school grade:
0.39 x (words / sentences) + 11.8 x (syllables / words) - 15.59
A result of 8 means a typical eighth grader should be able to read the text. Lower is easier.
Both formulas have limits. They do not understand meaning, jargon, structure or tone. A short sentence full of obscure terms can score well, and a clear sentence with one long technical word can score poorly. Use the scores as a signal, not a verdict.
Does readability affect SEO?
There is no evidence that Google uses a readability formula as a ranking factor, and Google has not documented one. Readability matters for indirect reasons:
- Satisfying the searcher. Google's guidance focuses on helpful, people-first content. Copy that people can understand quickly is more likely to meet that bar.
- Quotability in AI search. Answer engines lift short, self-contained passages. A direct two-sentence answer is easier to extract than a 60-word sentence with three clauses.
- Featured snippets. Concise definitions and clean lists are easier for Google to pull into snippet formats.
- Conversion. On product and landing pages, clear copy reduces friction. Visitors who understand the offer quickly are more likely to act on it.
For e-commerce and B2B brands, readability is often a revenue issue more than a ranking issue. Dense product descriptions and jargon-heavy service pages make visitors work harder than they want to.
How to use the QCK Readability Checker
- Open the Readability Checker.
- Paste the text you want to score. Use body copy only; leave out navigation, footers and code.
- Read the Flesch Reading Ease score and the grade level.
- Review the flagged sentences: these are the longest or hardest ones in your text.
- Rewrite the flagged sentences, then paste the revised text and score it again.
Score a few top-performing pages from your own site first. That gives you a realistic baseline for your audience instead of an arbitrary target.
How to read the results and improve your copy
Pick the right target
For general consumer copy, a Flesch score of 60 or higher (roughly grade 8 to 9) is a sensible goal. Technical B2B audiences can handle harder text, but even experts prefer clear writing. Do not force specialist copy to a grade 5 level if that means removing precise terms your buyers search for.
Fixes that move the score
- Split long sentences. If a sentence has two ideas joined by "and" or "which", make it two sentences.
- Swap long words for short ones. "Use" instead of "utilize", "help" instead of "facilitate", "buy" instead of "purchase".
- Cut filler. Phrases like "in order to", "it is important to note that" and "at this point in time" add syllables and no meaning.
- Use active voice. "We ship orders in 24 hours" is shorter and clearer than "Orders are shipped by our team within 24 hours".
- Use lists. Specs, steps and benefits are easier to scan as bullets.
Fixes the score will not show
Structure matters as much as sentence length. Lead with the answer, use descriptive headings, and keep paragraphs short. The heading tags guide covers outline structure.
Readability tips and mistakes to avoid
- Do not write choppy text to game the score. A string of four-word sentences scores well and reads badly. Vary sentence length.
- Keep the keywords your customers use. If buyers search for a technical term, use it and explain it.
- Edit the intro hardest. The first two sentences decide whether people stay and whether AI tools can quote you. See the AEO checklist for more.
- Read it aloud. If you run out of breath, the sentence is too long.
Clear copy improves both rankings potential and conversion rate. Our conversion rate optimization team tests copy changes on high-traffic pages, and our AI search optimization work restructures content so assistants can cite it.