How to use the Readability Score Checker
- Paste your text into the box — or click Sample to see how it works.
- Read the Flesch Reading Ease score and the grade levels: for most web content aim for 60+ and grade 8 or lower.
- Look at the highlights: long sentences are shaded and complex words underlined. Split long sentences and swap long words for short ones.
- Edit right in the box — the scores update as you type.
The six readability formulas
| Formula | Based on | Result |
|---|---|---|
| Flesch Reading Ease | Words per sentence, syllables per word | 0–100, higher is easier |
| Flesch–Kincaid Grade | Same inputs, scaled to US school grades | Grade level |
| Gunning Fog | Sentence length and words of 3+ syllables | Years of schooling |
| SMOG | Words of 3+ syllables per 30 sentences | Grade level (best for 30+ sentences) |
| Coleman–Liau | Letters per word and sentences per 100 words | Grade level |
| Automated Readability Index | Characters per word and words per sentence | Grade level |
Syllables are counted with English pronunciation rules (silent final “e”, “-es” and “-ed” endings, vowel groups), so the results match other readability tools closely but not always exactly. The scores are designed for English text.
Why readability matters for SEO
Search engines don’t use a readability score directly, but readers do: easy text keeps people on the page, answers their question faster and gets shared more. Most successful web pages land between grade 6 and 9. Check the length and keywords too with the Word Counter and Keyword Density Checker.
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Tools that pair well with the Readability Score Checker
- Character Counter — Count every character as you type — with and without spaces, letters, numbers, punctuation, emoji and bytes — and see instantly whether your text fits the limits of X, SMS, Google and social platforms.
- Case Converter — Paste any text and convert it between 11 letter cases — from Title Case for headlines to camelCase and snake_case for code.
- SERP Preview — Write a title tag and meta description and see exactly where Google is likely to cut them off — measured in pixels, not just characters, on desktop and mobile.
- SEO Checker & Site Audit — Paste a URL to run up to 70 on-page SEO checks plus a full site audit: Lighthouse speed, security headers & SSL, structured data, broken links, robots.txt & AI crawlers, accessibility basics, tracking & consent, SPF/DKIM/DMARC and domain expiry — rolled up into one site score with prioritized fixes.
Frequently asked questions
What is a good Flesch Reading Ease score?
60–70 is plain English that most adults read easily. 70–80 is fairly easy, 50–60 fairly difficult, and below 30 is academic or legal text. For web pages, aim for 60 or higher.
What grade level should web content be?
Grade 8 or lower for general audiences. Even experts prefer simple text when they are scanning a page, so a lower grade rarely hurts.
How do I improve my readability score?
Split long sentences, use shorter everyday words instead of long ones, and prefer active voice. The highlights show which sentences and words pull the score down.
Does it work for other languages?
The formulas and syllable rules are for English. Other languages have their own formulas, so scores for them are only rough guides.
Can I install Readability Score Checker as a web app and use it offline?
Yes. Readability Score Checker is an installable web app (PWA) — installed from your browser, not downloaded from an app store. Click Install app at the top of this page in Chrome or Edge (Windows, macOS, Linux, ChromeOS) or on Android, use Share → Add to Home Screen on iPhone and iPad, or File → Add to Dock in Safari 17+ on a Mac. It then opens in its own window with its own icon, and because it runs entirely in your browser it keeps working offline. Firefox on desktop can’t install web apps. How installing works.