Readability scores sound simple — paste your text, get a number, done. But the number is only useful if you understand what it actually measures.
The Two Scores You'll Encounter Most
Flesch-Kincaid Reading Ease runs from 0 to 100. Higher means easier:
| Score | Reading Level | Audience |
|---|---|---|
| 90–100 | 5th grade | Very easy, children's books |
| 70–80 | 6th grade | Easy, conversational |
| 60–70 | 7th–8th grade | Standard, most web content |
| 50–60 | High school | Fairly difficult |
| 30–50 | College | Difficult |
| 0–30 | Professional | Very confusing |
For web content, aim for 60–70.
Gunning Fog Index gives you an approximate grade level (US education system). A score of 8 means 8th-grade level. It counts words with 3+ syllables as "complex". Aim for 8–10 for general audiences; technical docs can go to 12.
What These Metrics Don't Measure
Both scores only look at sentence length and word length. They don't measure:
- Whether your argument is logical
- Whether jargon is appropriate for your audience
- Whether your structure helps readers navigate
- Whether your examples are clear
A sentence like "Run npm ci in the project root" would score as "very easy" because the words are short — but it's meaningless to someone who doesn't know Node.js.
When Scores Actually Help
Marketing copy: Aim for Flesch 70+. If you're below 60, you're probably writing for yourself.
Technical docs: Flesch 50–65 is fine. Keep surrounding sentences short even if technical terms are long.
Email: Flesch 70+ consistently performs better. Cut adjectives, shorten paragraphs.
Five Fixes That Actually Improve Scores
- Split long sentences at conjunctions — "and", "but", "so", "because" are natural break points
- Kill passive voice — find "was/were + verb" and invert it
- Collapse noun stacks — "the configuration update process" → "updating the config"
- Replace abstract nouns — "utilisation" → "use", "implementation" → "build"
- Remove hedges — cut "somewhat", "fairly", "quite", "rather"
Check Your Own Writing
The SnappyTools Readability Checker gives you Flesch-Kincaid, Gunning Fog, reading time, and sentence length distribution in one pass. It highlights long sentences so you can fix them directly instead of rewriting everything.
No account needed. Paste text, get results, fix what's broken.
What kind of writing do you most often need to simplify? Technical docs, marketing copy, or something else?