Free Readability Checker

A readability checker estimates how easy a piece of text is to read. The free Readability Checker scores your text with the Flesch reading ease formula and flags long sentences, long paragraphs and passive voice. It runs in your browser, so the text you paste is not uploaded or stored.

People rarely read every word: Nielsen Norman Group eyetracking research on reading patterns says people scan webpages and phone screens in various patterns, one of them shaped like the letter F, so short sentences and paragraphs help your point get seen.

How to use the Readability Checker

1. Paste your text into the box.
2. Run the check.
3. Read the Flesch reading ease score first.
4. Go through the flagged long sentences, long paragraphs and passive voice.
5. Rewrite the flagged parts, then check again to see the score move.

Check a section at a time on a long page. A single score for ten thousand words hides where the hard parts are.

How to read the results

The Flesch reading ease formula is based on sentence length and word length. A higher score means easier text, and a lower score means harder text. The formula looks at shape, not meaning, so it cannot tell whether your content is clear or correct.

• Higher score: short sentences and short words. Suits a general audience.
• Lower score: long sentences or long words. Fine for a specialist reader, hard for everyone else.
• Long sentences: flagged because they ask the reader to hold too much at once.
• Long paragraphs: flagged because walls of text are hard to scan.
• Passive voice: flagged because it can hide who is doing what. It is not always wrong.

Decide your target by audience. A guide for customers should read easily. A technical paper for engineers can read harder.

How to improve a low score

1. Split any sentence with more than one main idea into two.
2. Replace long words with plain ones where the meaning stays the same.
3. Cut filler phrases that add length and no meaning.
4. Turn passive sentences into active ones: “The team reviewed the page” instead of “The page was reviewed by the team”.
5. Break long paragraphs where the topic shifts.
6. Add subheadings so readers can find their place.

Worked example (illustrative)

Imagine this sentence: “The implementation of the optimisation of page assets was undertaken by the development team in order to facilitate improved loading.” The checker flags it as long and passive.

Rewrite it as “The development team compressed the page images so the page loads faster.” It is shorter, active and uses plainer words, and the score improves. This is an example only. The tool shows where to look, and you choose how to rewrite.

Why it matters for SEO

Readable text keeps people on the page. A reader who follows your argument is more likely to finish, trust you and act. Search engines aim to show results that satisfy people, so writing that is easy to follow serves the same goal even though the score is not a ranking input. Clear writing also helps visitors who are reading in a second language or on a small screen.

Limits of readability scores

Formulas count syllables and sentence length, nothing else. A short sentence full of jargon can still score as easy, and a clear but long sentence can score as hard. Passive voice detection is also approximate. Use the flags to find places to look, then use your judgement.

Readability is not a direct ranking factor you can chase. It matters because easier pages are more likely to be understood and finished. To check the length of the text at the same time, use the Word and Character Counter.

Read your text aloud once after editing. Anywhere you run out of breath or stumble is usually a sentence worth splitting, whatever the score says.

If several writers work on your site, agree a rough target for sentence length and paragraph size. Running each draft through the checker before it is published keeps the voice steady and makes editing quicker.

Questions about the Readability Checker

Browse the rest of the free content and writing tools or the full free SEO tools list. If you would rather have someone review your pages with you, see my on-page optimisation service or ask for a free audit.