Readability Analyzer: Flesch Reading Ease Score

The score needs only three counts: words, sentences and syllables. Everything else follows from this formula:

score = 206.835
        - 1.015 x (words / sentences)
        - 84.6  x (syllables / words)

Take this two-sentence sample:

"Most people skim a web page before they decide to read it. Short sentences and common words help them find the answer quickly."

The analyzer counts 23 words, 2 sentences and 31 syllables. That is 11.5 words per sentence and about 1.35 syllables per word:

206.835 - (1.015 x 11.5) - (84.6 x 1.348)
= 206.835 - 11.67 - 114.03
= 81.1   ->  "6th Grade - Easy"

Notice the weights. One extra syllable per word costs far more than one extra word per sentence, so swapping long words for short ones usually moves the score more than splitting sentences does. Results below 0 or above 100 are shown as 0 and 100.

The right target depends on who is reading, not on a universal rule. These ranges are common editorial guidance rather than hard limits:

A specialist audience does not need a score of 80, and forcing one can make precise writing vague. A better habit is to compare like with like: test your draft against pages you consider clear on the same topic, and aim for the same range.

A readability score is not a Google ranking factor. Google has not said that it uses Flesch or any similar formula, and raising your score from 55 to 65 will not move a page by itself.

What Google does try to reward is content that satisfies the person who searched. Clear writing helps with that: readers find the answer sooner, fewer of them return to the results page to try another site, and clear pages are easier to quote and link to. Treat the score as a proxy for effort the reader has to spend, not as a metric to maximise.

Using this as an SEO readability tool

1. Paste the introduction on its own. It is the first thing a visitor reads, and it is often the densest part of a draft.
2. Check each long section separately to find the one that drags the average down.
3. Rewrite the worst sentences, then confirm you kept the terms people search for with the keyword density checker.
4. Check overall length with the word counter, and make sure the title and description read just as plainly in the Google preview simulator.

Both versions below say the same thing. The scores are the ones this analyzer returns.

Before: score 0 (College Graduate - Very Difficult)

"In order to facilitate the optimization of website performance, it is recommended that the implementation of image compression be undertaken by site administrators prior to the publication of any additional content."

One sentence, 31 words, about 2.2 syllables per word, passive voice throughout.

After: score 77.6 (7th Grade - Fairly Easy)

"Compress your images before you publish a new page. Smaller files load faster, so visitors wait less. You do not need special software to do it."

Three sentences, 26 words, about 1.4 syllables per word. The changes were mechanical: name who does the action ("you"), replace noun phrases with verbs ("the implementation of image compression" became "compress"), cut filler such as "in order to", and give each idea its own sentence.

The analysis runs in your browser as you type; your text is not sent anywhere. Knowing how the counts are made helps you read the result correctly.

• Syllables are estimated from vowel groups using rules for English, plus a short list of exceptions for common irregular words. The estimate is close on ordinary prose and less reliable on names, abbreviations and loanwords.
• Only English words are counted. Numbers and symbols are skipped, and text in other languages gets no score.
• A sentence ends at a full stop, question mark or exclamation mark followed by a space, whether or not the next word is capitalised. Decimals such as 3.5, web addresses, initials and common abbreviations such as "Dr.", "e.g." and "etc." do not end a sentence. Unusual abbreviations can still be read as a sentence break, which pushes the score up slightly.
• Every line break also ends a sentence, so a heading or a bullet point without end punctuation is counted as its own short sentence. A page with many headings and short list items will therefore look easier than its body text is; test body paragraphs on their own for a fair number.
• Very short samples swing widely. A single long word changes the result of a 20-word sample; 100 words or more gives a steadier number.
• Reading time assumes about 200 words per minute and is rounded up to a whole minute.

The tool reports the Flesch Reading Ease score with its grade label, words per sentence, syllables per word, sentence count and reading time. It does not check grammar, passive voice or spelling, and the formula knows nothing about meaning: a short sentence full of undefined jargon can score well and still confuse readers. Use the number to find problem passages, then judge them yourself.

The Flesch Reading Ease score is one of the oldest and most widely used readability formulas, developed by Rudolf Flesch in 1948. The formula produces a score between 0 and 100, where higher scores indicate easier-to-read text. This score has become the industry standard for measuring text complexity and is used by everyone from journalists to government agencies to ensure their content is accessible.

The formula calculates the score using two factors: the average number of words per sentence and the average number of syllables per word. Shorter sentences and words with fewer syllables result in higher scores. The mathematical formula is: 206.835 - (1.015 × average sentence length) - (84.6 × average syllables per word).

Readability is a critical but often overlooked factor in SEO success. While search engines don't directly measure readability scores, they do measure user engagement metrics that are heavily influenced by how easy your content is to read. Understanding this connection is essential for creating content that ranks well and converts visitors.

When visitors land on your page and find the content easy to understand, they're more likely to stay longer, read more, and engage with your calls to action. This increased "dwell time" sends positive signals to search engines, indicating that your content satisfies user intent. Conversely, difficult-to-read content leads to quick exits (bounces), which can negatively impact your rankings over time.

Studies have shown that the average American adult reads at an 8th-grade level, yet many websites publish content written at a college level or higher. This mismatch creates friction that drives visitors away. By aiming for a 60-70 Flesch score, you write in plain English that most adult readers can follow comfortably, which widens your potential audience.

Readable content also increases the likelihood of social sharing and backlinks. People are more likely to share content they understand, and other websites are more likely to link to resources that their audience can easily consume. These social signals and backlinks are direct ranking factors that boost your SEO performance.

Mobile users, who now represent the majority of web traffic, are particularly sensitive to readability. Reading on small screens is already challenging, and complex content becomes even more difficult to consume. Optimizing readability for mobile users improves their experience, reduces bounce rates, and signals to Google that your site provides a good mobile experience—another important ranking factor.

Improving your content's readability doesn't mean dumbing it down—it means communicating more effectively. Here are proven strategies used by professional writers to create content that's both accessible and engaging.