About Readability Checker
Readability Checker measures how easy your writing is to read and shows you exactly what to fix. Paste a blog post, email, essay or landing page to get six standard readability scores and highlights for hard sentences.
How it works
Readability formulas estimate difficulty from measurable features of the text: how long the sentences are, and how long or complex the words are. The tool counts sentences, words, syllables and characters, then applies six well-known formulas:
- Flesch Reading Ease: a 0–100 score where higher is easier. 60–70 is plain English.
- Flesch-Kincaid Grade Level: the US school grade needed to follow the text.
- Gunning Fog Index: weighs heavily on long, multi-syllable words.
- SMOG Index: often used for health and public-information writing.
- Coleman-Liau Index and Automated Readability Index: based on characters per word instead of syllables.
The Highlights view marks very long sentences, passive voice ("the report was written by…") and adverbs, the three most common reasons writing feels heavy.
Tips for better readability
- Keep the average sentence under 20 words. Split any sentence highlighted as very hard.
- Prefer short, common words: "use" instead of "utilize", "help" instead of "facilitate".
- Use the active voice: "We fixed the bug" is clearer than "The bug was fixed".
- Aim for a grade level of 7–9 for blogs and marketing pages, the range most popular writing targets.
- Break long paragraphs up and use headings and lists. Scores don't measure layout, but readers notice it.
Good to know: formulas measure difficulty, not quality. Technical terms can raise the grade level even in excellent writing. Use the scores as a guide, not a rule.