Readability Checker
Score your writing with 7 readability formulas. See grade level, difficulty highlights, and improvement suggestions.
Target audience
Determines whether the overall grade fits your readers.
About this tool
Score your writing with seven readability formulas — Flesch Reading Ease, Flesch–Kincaid Grade Level, Gunning Fog, Coleman–Liau, SMOG, Automated Readability Index, and Dale–Chall — and see exactly which sentences are dragging your grade level up.
Pick a target audience (children, general, professional, or academic) and the checker tells you whether your text is a fit. The annotated text view highlights moderate and hard sentences inline so you can rewrite the offenders without scanning for them.
Suggestions cover the three most common readability problems: long sentences, complex vocabulary, and overall difficulty. Use them as a checklist; rerun the analysis after each edit to see your score move.
How to use the checker
Paste your text into the input. The checker computes seven readability scores live, surfaces an overall grade level, and highlights individual sentences that are dragging the score up. The sentences flagged as moderate or hard are the ones to focus your editing on — usually shortening them is enough to drop the overall grade by a level or two.
The audience selector lets you pick a target: children (grade 4–5), general public (grade 7–8), professional (grade 10–12), or academic (grade 13+). The checker then tells you whether your text matches the selected audience and what to adjust to fit.
The seven formulas
| Formula | Output | What it weighs |
|---|---|---|
| Flesch Reading Ease | 0–100 (higher = easier) | Sentence length + syllables per word |
| Flesch–Kincaid Grade | Grade level | Same inputs as Reading Ease, different output |
| Gunning Fog | Grade level | Sentence length + percentage of 3+ syllable words |
| Coleman–Liau | Grade level | Characters per word + sentences per 100 words |
| SMOG | Grade level | Polysyllabic word density (medical-comms origin) |
| Automated Readability Index | Grade level | Characters per word + words per sentence |
| Dale–Chall | Score (mapped to grade) | Words outside a 3,000-word "easy" list |
Different formulas use different inputs, so they'll sometimes disagree. Look for consensus — when five of the seven formulas land in the same grade range, that's your real score. When the spread is wide (e.g., 8 to 13), something unusual is happening: short sentences with technical vocabulary, or long sentences with simple words.
What's a good score?
It depends on your audience.
- General web content for adults: grade 6–8 (Flesch Reading Ease 60–80)
- News articles: grade 8–10 (Flesch Reading Ease 50–60)
- Government plain-language guidance: grade 6–8 (Flesch Reading Ease 60+)
- Healthcare patient information: grade 6 or below
- Academic / professional: grade 13+ (Flesch Reading Ease 30 or below)
For the full reference of what each grade level means and how to interpret each formula, see our guide on what is a good readability score.
How to improve readability
If the score is too high (text too hard for the audience), the levers in order of impact:
- Shorten sentences. Aim for an average of under 20 words. Splitting a 30-word sentence into two 15-word sentences typically drops the score by a full grade.
- Replace polysyllabic words with simpler synonyms. Utilise → use; approximately → about; demonstrate → show.
- Break up long paragraphs. Doesn't directly affect formula scores but improves perceived readability.
- Cut hedge phrases. "It might be the case that" → "Possibly".
- Read aloud. Anywhere you naturally stumble is a candidate for revision; the formula often catches the same sentence.
The annotated text view highlights moderate-difficulty sentences in amber and hard sentences in red, so you can find the offenders without manually scanning.
What the formulas don't measure
Readability scores are useful proxies, not the whole picture. They measure the floor of comprehensibility — whether your prose is unnecessarily hard — not the ceiling of quality. They don't capture voice, rhythm, logical structure, or reader engagement.
Use them as a sanity check on early drafts and a target for plain-language writing requirements. Don't optimise blindly to the number — well-written grade-10 prose often outperforms ham-fistedly simplified grade-6 prose.
Privacy
Analysis runs entirely in your browser. The full text never reaches our servers.
Frequently asked questions
What is a good Flesch Reading Ease score?
60–70 is "plain English" — comfortable for most adults. Below 30 is academic/specialist territory. Above 80 is conversational, appropriate for children's books and accessible health content. Web content for general audiences typically aims for 60+.What grade level should I write at?
Match the audience. General-public content (news, blog posts): grade 7–9. Web copy aimed at conversion: grade 6–8. Academic writing: grade 13+. Plain-language guidance for government and health writing recommends grade 6–8.How is reading level calculated?
Most formulas combine sentence length and word complexity. Flesch–Kincaid uses syllables per word; Coleman–Liau uses characters; Dale–Chall uses a curated 3,000-word "easy" list. Scores converge for typical prose but diverge for technical writing or very short text.What is the Gunning Fog Index?
A grade-level estimate combining average sentence length with the percentage of "complex words" (≥3 syllables). Formula: 0.4 × (words/sentences + 100 × complex/words). A Fog Index of 12 means the text needs a high-school senior's reading skill.How can I make my writing more readable?
Shorten sentences (aim for under 20 words on average). Replace polysyllabic words with simpler synonyms. Break long paragraphs. Use the active voice. Read your work aloud — anywhere you stumble is a candidate for revision.