Reading-level analyzer
Paste text to get its US grade level scored four different ways, plus targeted tips on which sentences and words are dragging the score down. Everything runs in your browser.
Suggestions
Add text to see what to simplify.
How to read the scores
We compute four scores because each one has blind spots. Flesch-Kincaid and Gunning Fog reward shorter sentences and simpler words but are syllable-based, which penalises clear long words like “information.” Coleman-Liau is letter-based, so it holds up better with technical jargon and acronyms. SMOG is designed for health communication and is widely cited by the US National Institutes of Health. If three of the four scores agree on a grade, that’s the most reliable estimate.
Most newsroom style guides target US grade 8-10 for news copy. Plain-English government writing targets grade 6-8. Academic papers sit at grade 14-18. If you are writing a public-facing essay or article, aim for Flesch reading-ease above 60.
About the Reading level
The reading level analyzer scores how hard your text is to read using five established formulas at once: Flesch reading-ease, Flesch-Kincaid grade, Gunning Fog, SMOG, and Coleman-Liau. Alongside the scores it flags specific problems, over-long sentences, very long or many-syllable words, and likely passive voice, so you know not just that the text is dense but where to fix it.
It is built for anyone who needs writing to land with a broad audience: content writers, teachers, support and policy teams, and students checking an essay's tone. Most readability targets are expressed as a US school grade, and seeing several formulas together is more trustworthy than relying on any single one, since each weighs sentence length and word difficulty a little differently.
How to use it
- Paste an essay, blog post, or email into the editor, or load the sample to see the tool in action.
- Read the large Flesch reading-ease score and its plain-language band on the gauge.
- Compare the four grade-level scores: Flesch-Kincaid, Gunning Fog, SMOG, and Coleman-Liau.
- Work through the Suggestions list, which names over-long sentences, hard words, and passive constructions.
- Edit the flagged spots, then watch the scores and average sentence length update as you simplify.
Examples
Bring a policy page down to grade 8
A benefits page scores Flesch reading-ease 38 with a Flesch-Kincaid grade near 13, far above the grade 8 most adults read comfortably. The suggestions flag three sentences over 28 words and several four-syllable words. You split the sentences and swap in plainer terms, lifting reading-ease into the 60s.
Tighten a passive draft
An email reads stiffly. The analyzer reports several likely passive constructions, such as the report was reviewed by the team. You rewrite them in active voice, the report became we reviewed, and the prose reads more directly without the grade level changing much.
Frequently asked questions
- How is Flesch reading-ease calculated?
- It uses 206.835 minus 1.015 times the average words per sentence minus 84.6 times the average syllables per word. Higher is easier: 90 to 100 reads at about 5th grade, 60 to 70 is standard 8th to 9th grade, and below 30 is very difficult college-graduate prose.
- Why do the grade-level scores not match each other exactly?
- Each formula weighs difficulty differently. Flesch-Kincaid and SMOG lean on syllables, Gunning Fog counts words of three or more syllables as complex, and Coleman-Liau ignores syllables entirely and uses letters per word instead. A cluster of close scores gives you a more reliable reading than any one.
- How does it count syllables?
- Syllables are estimated by grouping vowel sounds, with adjustments for silent endings like a trailing e and short words. It is a heuristic, so an unusual or technical word can be off by one, but across a full passage the small errors average out.
- What triggers the passive voice flag?
- It looks for a form of to be, such as is, was, or were, followed by a word ending in ed or en, the typical shape of a passive construction. It is a rough detector, so it can miss some passives and occasionally flag a false positive, but it reliably surfaces the most common cases.
Good to know
Readability formulas measure sentence length and word complexity, not meaning, logic, or accuracy. A text can score easy and still be badly organised, and a difficult score is sometimes unavoidable for genuinely technical material aimed at experts. Use the numbers as a prompt to shorten sentences and prefer plain words where you can, not as a goal to hit by chopping every sentence to the same length, which produces choppy, monotonous prose.
For general audiences, grade 8 to 9 is a common target, since it is roughly the average adult reading level and keeps the door open to the widest readership. Plain-language guidance for health and government often aims lower still, around grade 6 to 7. Match the target to your readers rather than chasing the lowest possible score; a specialist audience can handle, and may prefer, denser prose with precise terminology.