A readability checker scores how easy your writing is to read and tells you the school grade a reader needs to follow it. Paste any text — an article, a landing page, an email — and this one computes five industry-standard formulas live as you type: Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog, SMOG and the Automated Readability Index, alongside word and sentence counts, syllable density, estimated reading time, and a list of your longest sentences flagged as rewrite candidates. It runs entirely in your browser: nothing you paste is uploaded or stored, and there's no signup.
Readability is where good content quietly fails. Dense copy makes visitors skim, and skimmers don't convert, link or come back; a 40-word opening sentence buries the answer a searcher came for; and passages that take three reads never get quoted by featured snippets or AI answer engines, which lift short, plainly worded statements they can extract cleanly. Literacy research consistently places the average US adult's comfortable reading level around 7th to 8th grade — writing at a 14th-grade level doesn't make a page look smarter, it just shrinks the audience that finishes it.
Use this readability test to score and tighten one page at a time before you publish. It's the manual version of the content-quality checks Black & Gold SEO runs across an entire site — finding the pages where dense copy, thin sections and unanswered questions are costing rankings, then shipping the fixes.
How to use it
- 1
Paste your text
Drop in the full article or page copy — body text works best, since navigation labels and button text just add noise. The formulas stabilize around 100+ words, so score a whole draft rather than a single paragraph. Everything is computed locally in your browser as you type; use the sample text link if you want to see the scores in action first.
- 2
Read the verdict first
The verdict chip shows a consensus reading level averaged across the grade-based formulas. For general web content you want roughly 7th–9th grade; B2B and technical audiences tolerate 10th–12th. If the verdict is already in range for your audience, you're done — the individual scores below it are for diagnosis, not for chasing.
- 3
Use disagreements between formulas to diagnose the problem
The five formulas measure different things, so their spread tells you what to fix. A high Gunning Fog with a decent ARI means too many three-plus-syllable words — swap them for shorter ones. A high ARI or Flesch-Kincaid with a decent Fog means sentences run long — split them. When all five run high, do both.
- 4
Rewrite the longest sentences
The rewrite panel lists your five longest sentences with word counts. Sentences over 25 words are where comprehension drops fastest, so splitting each into two is usually the single highest-leverage edit you can make — and because every formula weights sentence length, it improves all the scores at once.
- 5
Re-check and ship
Edit, watch the scores update live, and stop when the verdict matches your audience — don't chase a perfect number. Then run every future draft through the same readability score checker before it goes live; it takes seconds and catches the dense passages editors reading their own work always miss.
For most web content the target is a Flesch Reading Ease of 60–70 — plain English — which corresponds to roughly a 7th–9th grade level on Flesch-Kincaid, Gunning Fog and ARI. That is not dumbing down. Readability formulas only measure structure: words per sentence, syllables per word, characters per word. You can explain genuinely advanced material at an 8th-grade level by letting short sentences and short words carry expert ideas — the writers people actually finish reading do exactly that. The reverse is also true: a page can score 90 and still be vague or wrong, because no formula reads meaning. Treat the score as a smoke detector, not a quality certificate.
In 2026 readability has a second job: extraction. AI answer engines and featured snippets quote short, self-contained sentences that state a fact plainly — a key claim buried mid-way through a 45-word sentence with three subordinate clauses rarely gets lifted. Writing scannable, plainly worded passages is now as much about being citable as being pleasant to read. Know your formulas, too: Flesch Reading Ease and Flesch-Kincaid are the general-purpose defaults; Gunning Fog is strictest about long words and suits business writing; SMOG is the standard in healthcare communication, where misreading has real consequences — and it's only valid on samples of 30+ sentences, which is why this tool withholds it below that; ARI uses characters instead of syllables, making it the most sensitive to long technical terms.
Two honest caveats. First, English syllables can't be counted perfectly by rule — this tool uses a vowel-group heuristic with silent-e and common-suffix handling, the same approach most readability software takes, so expect scores within about a point of a hand count rather than an exact match with every other tool. Second, readability is the last editing pass, not the first: get the substance right, then score, split your longest sentences, swap heavy words, and stop. Moving a page from 45 to 65 Flesch Reading Ease is a real win; the last five points are rarely worth the hour.
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