Free Readability Checker

How to use the readability checker free tool

1. Paste the body text of your page, article or email into the box. Paste prose only: headings, menus and bullet items without a full stop can run into the next line and count as one very long sentence.
2. Read the scores. Reading ease runs from 0 to 100, where higher is easier. Grade level shows the school year needed to follow the text.
3. Look at the highlighted sentences. Orange marks long sentences over 25 words; blue marks possible passive voice.
4. Edit the highlighted sentences, paste the new version and check that the score improves.

What your readability checker free results mean

• 70 to 100: easy to read. Good for most consumer websites and service pages.
• 60 to 69: plain English. A good target for blogs and business content.
• 50 to 59: fairly difficult. Acceptable for specialist or technical audiences.
• 30 to 49: difficult. Readers may skim or leave. Break up sentences and simplify words.
• Below 30: very difficult, typical of dense legal or academic prose.
• Grade level: aim for about 7 to 9 for content written for the general public.

The coloured label above the highlighted sentences follows the same bands: green from 60 upwards, amber from 40 to 59 and red below 40. The score shown is limited to the range 0 to 100, and the grade level never drops below 0, so very short or very simple text can display 100 even though the raw formula would give a higher number.

How the readability checker free formulas work

The tool uses the two best-known Flesch and Flesch-Kincaid readability tests. Both use only two ratios: average words per sentence and average syllables per word.

• Flesch Reading Ease = 206.835 − 1.015 × (words ÷ sentences) − 84.6 × (syllables ÷ words)
• Flesch-Kincaid Grade Level = 0.39 × (words ÷ sentences) + 11.8 × (syllables ÷ words) − 15.59

The coefficients show where your effort pays off. One extra word in the average sentence costs about 1 point of reading ease. One extra tenth of a syllable per word costs about 8.5 points. In practice, replacing “utilise” with “use” or “commence” with “start” moves the score far more than trimming a sentence by a word or two.

Worked example: two versions of the same advice

• Version A: 15 words per sentence and 1.4 syllables per word gives a reading ease of about 73 and a grade level of about 6.8. That is easy to read.
• Version B: 25 words per sentence and 1.7 syllables per word gives a reading ease of about 38 and a grade level of about 14.2. That is difficult, and closer to a journal article.

Both versions can say the same thing. The difference comes from sentence length and word length, which are the two things you control when you edit.

How this readability checker free tool counts words, syllables and passive voice

Every readability checker free of charge or paid makes simplifying choices. Knowing them helps you read the numbers correctly.

• Sentences are split at full stops, exclamation marks and question marks. Abbreviations such as “e.g.” or “U.S.” and web addresses contain full stops and can split a sentence in the wrong place, which makes the average sentence look shorter than it is.
• Words are runs of letters, apostrophes and hyphens. Numbers are ignored, and a hyphenated compound counts as one word.
• Syllables are estimated. Words under four letters count as one syllable. For longer words the tool removes common silent endings such as “es”, “ed” and a final “e”, then counts groups of vowels. This is right for most English words and wrong for some, so single words can be off by one while long texts even out. For stable scores, test at least 100 words.
• Complex words are words with three or more syllables, shown as a percentage of all words.
• Long sentences are sentences of more than 25 words.
• Passive voice is detected by pattern: a form of “to be” followed by a word ending in “-ed” or a common irregular participle such as “written”, “made” or “built”. It can miss passives built on rarer participles, and it can flag adjectives such as “is limited” or “was tired”. Treat the blue label as a prompt to look, not a verdict.

A workflow for editing with a readability checker free tool

1. Check one section at a time. A whole-page score averages out. A hard section hidden between easy ones only shows up when you paste it alone.
2. Fix long sentences first. Split them where a conjunction joins two separate ideas, so each sentence carries one point.
3. Simplify words, but keep your terms. Replace “utilise” with “use”. Keep technical words your readers search for, and explain each one the first time it appears.
4. Review each passive flag. Keep the passive when the actor does not matter (“the file is saved automatically”). Rewrite it when the actor does (“we saved the file”).
5. Paste the new version and compare. Stop when the grade level reaches your target. Chasing a score of 100 usually produces choppy writing.

Do not push the score up by chopping every sentence into a fragment. Formulas reward short sentences, but readers need rhythm. A mix of short and medium sentences reads better than a run of three-word ones, even when the second version scores higher.

Readability targets by content type

These are working guidelines, not rules. Pick the target from your audience, not from the formula.

• Service and landing pages: reading ease 60 to 75, grade 6 to 9. Visitors are comparing options quickly.
• Blog posts and guides: reading ease 55 to 70. You can go a little lower when the topic needs precise terms.
• Emails and sales messages: reading ease 60 or higher.
• Technical documentation: reading ease 40 to 55 is common. Define each term once and use short steps for instructions.

The US government’s plain language guidelines are a good reference for the habits behind the scores: write for your audience, use active voice, keep sentences short and put the most important point first.

Why readability matters for rankings and AI answers

Search engines do not use a readability score as a direct ranking factor. Google’s guidance on creating helpful, people-first content asks whether the content is easy to follow and written for readers, not for search engines. Readers also decide fast: Nielsen Norman Group research found that most web visitors scan a page rather than read it word by word, so clear headings, short paragraphs and plain words decide whether they stay.

AI search tools add a second reason. They pull passages that make a complete point on their own. A passage written in short sentences, familiar words and active voice is easier to lift into an answer and easier to quote correctly. Using a readability checker free on your key sections before you publish is a quick way to catch the passages that are too dense to be quoted.

Limits of any readability checker free tool

A readability score measures surface features of the text. It cannot tell you whether the content is accurate, whether the page answers the search, or whether the headings, layout and examples help. A page can score 80 and still be useless, and a specialist guide can score 45 and be exactly right for its readers.

The scores will also differ from the ones in your word processor or SEO plugin. Each tool splits sentences and counts syllables a little differently, so a gap of several points between tools is normal. Pick one tool, use it consistently and compare drafts against each other instead of against another tool’s number.

Frequently asked questions

What is a good Flesch Reading Ease score?

For most websites, 60 or higher. Content for specialists can sit lower, but clearer is almost always better.

Is passive voice always wrong?

No. It is useful when the action matters more than who did it. Too much passive voice, though, makes writing slow and vague.

Will improving readability raise my rankings?

Not on its own. It improves how people engage with your page, which supports the goals rankings are meant to deliver: visits, trust and enquiries.

Is this readability checker free to use?

Yes. The readability checker free tool has no sign-up and no limit on how many times you check your text.

Does the tool store or send my text anywhere?

No. The scoring runs in your browser, so the text you paste is not uploaded to our server.

Why is my score different in Word or my SEO plugin?

Each tool splits sentences and estimates syllables with its own rules, so scores can differ by several points. Use one tool consistently and compare your own drafts against each other.