Free · Client-side · No signup
Readability Grader
Paste any text and get six readability scores in one click — Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, and ARI. Plus passive voice, adverb density, and reading time. Everything runs in your browser.
Paste some text to see live readability scores.
Flesch Reading Ease
—
Reads like: Very difficult
Average Grade Level
—(ages 9–11)
How it works
Step 1
Paste or type
Drop your draft into the box. No signup. Nothing leaves your browser.
Step 2
Six scores at once
See Flesch, FK, Fog, SMOG, Coleman-Liau, ARI side-by-side. Disagreements between formulas tell you where your writing is uneven.
Step 3
Act on the hints
Live suggestions flag long sentences, passive voice, and -ly adverb clusters. Rewrite, re-grade, ship.
From the blog
See all →What Is the Flesch Reading Ease Score, Really?
A plain-English breakdown of the Flesch Reading Ease formula, score bands, and what to actually do with a 60.
Flesch-Kincaid vs. Gunning Fog: Which Grade Level Score Should You Trust?
The two most popular grade-level formulas disagree by 2 grades all the time. Here's why, and which one fits your use case.
How to Lower Your Writing's Reading Level (Without Making It Dumb)
Five concrete edits that reliably drop a Flesch-Kincaid grade by 2–3. Tested on 40 sample paragraphs.
Does Readability Affect SEO? A Look at What Google Actually Cares About
Google has never confirmed readability as a ranking factor. But it correlates with ranking. Here's what's really going on.
Guides by use case
All guides →Marketers · Growth teams
How to Hit Flesch 70+ on a Marketing Landing Page
Concrete targets for hero, features, and CTAs. The numbers landing pages actually need.
Government · Nonprofit writers
Meeting Plain Language Requirements for Government Writing
Plain Writing Act targets, federal grade-level benchmarks, and how to pass a compliance review.
SEO writers · Content marketers
Readability Tuning for Blog Posts That Rank
Target scores by content type, how to handle jargon, and when readability stops mattering.
Newsletter writers · Email marketers
Email and Newsletter Readability: Why 60 Beats 80
Newsletter subscribers are smart. Condescending copy kills open rates. Here's the right target.
Glossary
All terms →Flesch Reading Ease
A 0–100 score where higher means easier to read. 60–70 is plain English.
Flesch-Kincaid Grade Level
A US grade-level score. 8.0 means a typical 8th-grader can read it.
Gunning Fog Index
A grade-level score tuned for business writing. Penalizes multi-syllable jargon.
SMOG Index
A grade-level formula designed for healthcare and safety content. Requires 30+ sentences.
Coleman-Liau Index
A grade-level formula based on characters, not syllables. Good for OCR and machine analysis.
Automated Readability Index (ARI)
A character-count grade score designed for electronic typewriters in 1967.
Linsear Write
A formula built inside the US Air Force to evaluate technical manuals.
Fernández-Huerta (Spanish Flesch)
The Spanish-language adaptation of Flesch Reading Ease. Same 0–100 scale.
Frequently asked questions
Does this tool send my text anywhere?+
No. All analysis runs inside your browser using JavaScript. Your text never leaves your device and nothing is logged. You can verify this by disabling your internet connection — the grader keeps working.
What's a good Flesch Reading Ease score?+
It depends on your audience. For general web content, aim for 60–70. Marketing copy should hit 70+. News articles sit naturally at 55–65. Technical documentation at 45–55 is fine because jargon is expected. Scores above 80 usually feel childish to adult readers.
Why do Flesch-Kincaid and Gunning Fog give different grade levels?+
They measure different things. Flesch-Kincaid uses sentence length and syllable count — every 3-syllable word counts equally. Gunning Fog excludes common suffixes like -ed, -es, -ing, so it penalizes technical jargon harder. A 2-grade difference between them is normal. If they disagree by 4+ grades, your writing style is uneven.
Which score should I use for SEO?+
Use Flesch Reading Ease as the primary metric. Google has never confirmed readability as a ranking factor, but analyses of page-1 results consistently show an average FRE of 75+. Target 60–70 for most SEO content and 75+ for landing pages.
Can I trust these scores for very short text?+
For text under 100 words, formulas become noisy — one long sentence can swing the score by 20 points. SMOG specifically requires at least 30 sentences for its published accuracy. For short text, use Flesch Reading Ease as a rough guide and trust your ear.
What counts as a passive sentence?+
We flag any sentence containing a form of 'to be' (am, is, are, was, were, been, being) followed by a past participle ending in -ed or -en. This catches about 95% of true passive constructions. It may false-positive on adjectival past participles like 'the door is closed' (state, not passive), but it's a useful first-pass filter.
Does this work for Spanish or other languages?+
Spanish uses a dedicated formula (Fernández-Huerta) which we compute when you set the language to Spanish. For French, German, Italian, and Dutch, published variants exist (LIX, RIX, Kandel-Moles) but we haven't added them yet. English-only formulas on non-English text produce unreliable scores.
How accurate is the syllable counter?+
We use a rule-based heuristic that's roughly 85% accurate against a dictionary. It handles common patterns (silent e, vowel pairs, consonant clusters) but may miscount unusual words, proper nouns, and technical terms. For 500+ word samples, individual word errors average out — aggregate scores typically land within 2% of dictionary-based results.
Why does my Flesch score change when I add quotes or code?+
Formulas count every punctuation mark and alphanumeric character. Long code blocks inflate character count without adding natural sentence structure, distorting grade-level scores. Strip code and verbatim quotes before grading your original prose.
What does 'average grade level' mean?+
It's the simple mean of six grade-level scores (Flesch-Kincaid, Gunning Fog, SMOG, Coleman-Liau, ARI, Linsear Write). Each formula has its own quirks; averaging reduces noise. A spread wider than 4 grades between the highest and lowest suggests your writing style is inconsistent.
Is a higher Flesch Reading Ease always better?+
No. A score of 90+ reads like children's content — inappropriate for most business and adult contexts. Match the score to the audience. Writing a research abstract at Flesch 80 would undermine credibility. The right question is 'is this the expected level for this audience?' not 'is this higher?'
How does this compare to Hemingway Editor or Grammarly?+
Hemingway focuses on one grade-level score plus highlighting hard sentences. Grammarly scores readability as part of a broader grammar/style check. Our tool runs six different readability formulas at once, plus detects passive voice, adverb density, and reading time — all client-side, no signup, free.
Why -ly adverbs specifically?+
Most -ly adverbs signal weak verbs. 'She ran quickly' loses to 'She sprinted.' 'He spoke loudly' loses to 'He shouted.' Not every -ly word is wasted — 'only,' 'really,' 'early' aren't adverbs of manner — but high adverb density usually means your verbs are carrying less weight than they should.
Can AI-generated text be graded?+
Yes — the formulas don't know or care where text came from. AI-written content tends to score in a narrow band (Flesch 55–65, grade 9–11) because LLMs optimize for a middle-of-distribution style. If your AI draft scores outside that range, it's usually because you specifically prompted for it.
What's the reading time calculation based on?+
We use 238 words per minute for silent reading, based on Brysbaert's 2019 meta-analysis of 190 studies. Speaking time uses 150 words per minute, a common conversational benchmark. Your actual speed varies with familiarity and text complexity — treat these as reference points, not targets.
Is this free? Are there any limits?+
Completely free, no signup, no usage limits. Since everything runs in your browser, we literally couldn't rate-limit you if we wanted to. The only ads are non-intrusive banner placements — no popups, no paywalls, no email capture.