Readability Checker: Score and Simplify Your Text
Check a web page or a pasted draft for reading ease, sentence length, long sentences, word length and passive voice.
Most people skim web pages. If a sentence has to be read twice, many visitors simply leave, and a dense paragraph is also harder for an AI system to quote cleanly. A readability score turns that problem into a number you can track and improve.
This readability checker calculates Flesch Reading Ease for English, the Kandel-Moles adaptation for French and the Fernández Huerta formula for Spanish. Alongside the score it shows average sentence length, your longest sentences, word length and passive-voice hints, for a URL or for pasted text.
How to check readability
Paste text or a URL
Check a live page or paste a draft straight from your editor.
Read the score and the details
The headline score gives the overall level; the long-sentence list shows exactly where readers will struggle.
Rewrite and re-check
Split long sentences, swap long words for short ones and run the check again until the score suits your audience.
How the Flesch Reading Ease score works
Rudolf Flesch’s 1948 formula uses just two inputs, sentence length and word length in syllables:
Reading Ease = 206.835 − 1.015 × (words ÷ sentences)
− 84.6 × (syllables ÷ words)Higher means easier. Kandel and Moles adjusted the constants for French, and Fernández Huerta built an equivalent for Spanish, because typical word length differs between languages. Compare scores within one language, never across languages.
| Score | Flesch’s label | Approximate US school level |
|---|---|---|
| 90–100 | Very easy | 5th grade |
| 70–80 | Fairly easy | 7th grade |
| 60–70 | Plain English | 8th–9th grade |
| 50–60 | Fairly difficult | 10th–12th grade |
| 30–50 | Difficult | College |
| 0–30 | Very difficult | College graduate |
For a general audience, aim for 60 or higher. Specialist readers tolerate lower scores, but even experts read plain sentences faster.
What actually makes text hard to read
The score is a symptom. These are the causes the checker points to:
- Long sentences. Past about 25 words, readers start losing the thread. Split at “and”, “which” or “because”.
- Long words. “Utilize” for “use”, “in order to” for “to”, “approximately” for “about”.
- Passive voice. “The form must be submitted by the user” hides who acts; “Submit the form” is shorter and clearer.
- Stacked nouns, such as “website performance optimization strategy review”.
Before (31 words, Flesch ≈ 17):
In order to ensure that the optimization of your website is achieved
in an effective manner, it is recommended that the implementation of
the following changes is undertaken by your developer.
After (14 words, Flesch ≈ 84):
To get the most from your site, ask your developer to make these changes.Syllable counting varies slightly between tools, so treat any score as approximate.
Readability, SEO and AI answers
No search engine has said it uses a readability formula as a ranking signal, so don’t chase a number for Google’s sake. Readability matters because of people: clear pages keep visitors reading, answer the question faster and earn more trust, which is what Google’s helpful content guidance asks for.
It helps with AI search too. Short, self-contained sentences that state one fact each are easier to extract and quote accurately than long chains of clauses; the AI SEO checker looks at that answer-ready structure. Combine a good score with a clear outline from the heading checker and the page becomes easy to scan.
Mind the formula’s blind spots: short words can still be jargon (“SKU”, “CTR”, “API”), and a list of short fragments can score well while saying little. Use the score to find hard passages, then judge them yourself — and keep enough depth to avoid thin content.
Tips for more readable writing
- Aim for an average sentence length under 20 words, and mix short and medium sentences so the text doesn’t sound robotic.
- Give each paragraph one idea and keep web paragraphs to two or three sentences.
- Define a technical term the first time you use it, then use it consistently.
- Use lists for steps and options; a sequence buried in a paragraph is hard to follow.
- Read the text aloud — every place you stumble is a sentence to fix.
Limits to keep in mind
Readability formulas count syllables, words and sentences; they can’t tell whether text is accurate, logical or right for its audience, and different tools count syllables slightly differently, so scores vary. Passive-voice hints are pattern-based, so treat them as suggestions, not errors. For URLs, we read the text in the server HTML without running JavaScript. To check length alongside clarity, use the word counter.
Last updated Oct 30, 2026 by the Yes SEO team.
Readability Checker: frequently asked questions
What is a good readability score?
For general web content, a Flesch Reading Ease of 60 or above is a sensible target. Technical or professional audiences can handle lower scores, but shorter sentences help every reader.
Which readability formulas does the checker use?
Flesch Reading Ease for English, Kandel-Moles for French and Fernández Huerta for Spanish. Each adapts Flesch’s idea of sentence and word length to its language.
Is readability a Google ranking factor?
Not directly. Google hasn’t said it uses any readability formula. Clear writing helps indirectly, because people find and use the answer more easily.
How do I improve my readability score?
Shorten long sentences, replace long words with common ones, use active voice and break dense paragraphs into lists. The checker lists your longest sentences so you know where to start.
Can I check a web page instead of pasted text?
Yes. Enter a URL and the checker reads the page’s text from its HTML, or paste a draft to check it before you publish.