Check the readability score of any text or website instantly. Get your Flesch Reading Ease score, reading grade level, SEO readability checks, and sentence-by-sentence analysis — free, online, no account needed.
Results update instantly as you type. Minimum 100 words for accurate scores.
Scores are calculated using the same algorithms used by Yoast SEO, Grammarly, and Hemingway Editor. For most web content, aim for a Flesch score of 60–70.
These checks mirror what Yoast SEO and Rank Math use to evaluate content readability for search rankings.
💡 SEO Tip
Yoast SEO scores your content readability as part of its overall SEO score. Aim for green bullets across all checks for maximum WordPress SEO benefit.
Sentences highlighted by length — easy to spot where readers might lose their way.
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A readability score measures how easy your writing is to read and understand. It considers factors like sentence length, word complexity, syllable count, and paragraph structure to assign a numeric score that corresponds to a US school grade level.
Google's goal is to surface content that answers user questions clearly and efficiently. Content that is difficult to read has higher bounce rates, lower dwell time, and fewer social shares — all signals Google factors into rankings. Research by Yoast found that content with good readability scores consistently outperforms complex content on the same topic.
Our free online readability checker calculates six different formulas and gives you the same SEO readability checks used by Yoast SEO and Rank Math — so you can optimise your content before publishing.
Flesch Reading Ease score scale — aim for 60–70 for most web content.
Our automatic readability checker calculates all six major reading level formulas simultaneously. Here's what each one measures.
Most widely used. Scores 0–100 (higher = easier). The formula used by Yoast SEO, Grammarly, and most SEO readability tools.
Formula: 206.835 − 1.015(words/sentences) − 84.6(syllables/words)
Converts Flesch to a US school grade level. A score of 8 means the text is readable by an 8th-grader. Most web content should target grade 6–8.
Formula: 0.39(words/sentences) + 11.8(syllables/words) − 15.59
Estimates the years of education needed to understand the text. Focuses heavily on polysyllabic words (3+ syllables). Target: under 12.
Formula: 0.4 × (words/sentences + 100 × complex_words/words)
Simple Measure of Gobbledygook. Highly accurate for healthcare and medical content. Based on counting polysyllabic words across 30 sentences.
Formula: 3 + √(polysyllables × 30/sentences)
Uses character counts rather than syllable counts — making it more consistent for digital text. Outputs a US grade level.
Formula: 0.0588L − 0.296S − 15.8 (L = letters/100 words, S = sentences/100 words)
Uses characters-per-word and words-per-sentence. Designed for real-time readability monitoring. Produces a US grade level estimate.
Formula: 4.71(chars/words) + 0.5(words/sentences) − 21.43
Our SEO readability checker runs the same checks that Yoast SEO and Rank Math use to score your content. Getting all green bullets doesn't guarantee rankings — but it significantly improves user experience, time on page, and the likelihood that readers will share your content.
Shorten Your Sentences
Google data shows that the average user reads at a 7th–8th grade level. Keep average sentence length under 20 words. Break long sentences at conjunctions (and, but, because) or split them into two separate sentences.
Reduce Passive Voice
Passive voice makes text harder to follow ("the ball was kicked by John" vs "John kicked the ball"). Keep passive voice under 10% of sentences. Our checker highlights passive constructions so you can rewrite them.
Use Transition Words
Words like "however," "therefore," "additionally," and "as a result" help readers follow your argument. Yoast recommends at least 30% of sentences include a transition word or phrase.
Keep Paragraphs Short
Online readers skim. Paragraphs longer than 150 words create visual walls that drive users away. Aim for 2–4 sentences per paragraph maximum.
Use Subheadings
Subheadings (H2, H3) help readers navigate long content and improve scannability. Yoast flags sections longer than 300 words without a subheading.
Many users search for the Grammarly readability score or the Yoast readability checker online. Both tools measure readability, but they use different approaches — and neither is free for all features.
Grammarly uses the Flesch Reading Ease formula and displays a score from 0–100 on Premium plans. It focuses on writing clarity within documents but doesn't check SEO-specific readability factors like subheading distribution or transition words.
Yoast SEO uses Flesch Reading Ease plus 7 additional SEO-specific checks (sentence length, passive voice, transition words, etc.) It's built into WordPress but only works inside the post editor — you can't check competitor content or external URLs.
Free, instant, no account. Checks 6 readability formulas + 5 SEO checks + sentence highlighter. Works on pasted text or any live URL. All calculations run client-side — your text is never sent anywhere.
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You've checked your content's readability. Now make sure your title tags, meta descriptions, and image alt text are optimised too. SkySEOManager Pro bulk-generates all of them across your WordPress site in minutes with Gemini AI.
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