Everything runs in your browser. Words, sentences and syllables are tokenised locally; each formula is applied to those counts; nothing is uploaded, stored, or sent to a server. The page works offline once it's loaded.
Free Readability Score Checker
English onlyRuns entirely in your browser - no upload, no sign-up.
Your text
Reading grade level-Paste text to see the score
Flesch Reading Ease-Waiting for text
Per-formula breakdown
FormulaScoreGrade level
Flesch Reading Ease--
Flesch-Kincaid Grade--
Gunning Fog Index--
SMOG Index--
Automated Readability Index--
Coleman-Liau Index--
0words
0sentences
0syllables
0complex words
0avg words / sentence
0avg syllables / word
What is a readability score?
A readability score estimates how hard a piece of writing is to read, usually as a US grade level. This free checker computes six classic formulas at once (Flesch Reading Ease, Flesch-Kincaid, Gunning Fog, SMOG, Automated Readability Index and Coleman-Liau) so you can compare them and pick a target audience with confidence.
How to use
- 1Paste your text. Type or paste the article, page or paragraph into the box above.
- 2Read the summary. The big tiles show the consensus US grade level and the Flesch Reading Ease score with its plain-language band, so you know at a glance who can read it.
- 3Compare the formulas. Below the summary, every formula's raw score and grade equivalent are listed side by side. If they disagree, pick the one closest to your audience and edit until you hit the target.
Who it's for
- Bloggers and content marketers aiming for the Standard band (Flesch 60-70) so a general audience finishes the post.
- Technical writers checking that documentation lands at the grade level their support team expects.
- Students and academics matching an essay or abstract to the reading level of a target journal or audience.
- Editors and ESL teachers grading text complexity and spotting paragraphs that need to be cut or simplified.
- UX writers tightening onboarding copy to the 8th-grade target most product teams write to.
FAQ
Is the readability checker free?
Yes - 100% free, no sign-up, no length limit. The whole page runs in your browser; your text is never uploaded.
Which readability score should I trust?
For general web writing, Flesch Reading Ease and Flesch-Kincaid grade level are the two most widely used; aim for Reading Ease 60-70 (Standard, around 8th grade). For longer-form text with 30+ sentences, SMOG is the most reliable single grade-based formula. For short, factual prose, Coleman-Liau and ARI tend to agree.
How is Flesch Reading Ease calculated?
Flesch Reading Ease = 206.835 - 1.015 × (words / sentences) - 84.6 × (syllables / words). Higher is easier. 90-100 is very easy (5th grade), 60-70 is plain English (8th-9th), 30-50 is college-level, and below 30 is best understood by university graduates.
What is a good Flesch-Kincaid grade level for web content?
Most consumer web pages, news sites and product copy target Flesch-Kincaid grade 7 to 9. Lower it for landing pages and onboarding; raise it for engineering docs or academic writing. Aim where your real readers are, not at the lowest possible number.
How are syllables counted?
Each word is lower-cased and stripped of non-letters, then a regex counts vowel groups while removing silent endings like -e and -es. It is the standard English heuristic that textstat and similar libraries use - around 85-90% accurate, which is already much smaller than the 10-15% error built into the formulas themselves.
Why do the six scores disagree on the same text?
Each formula weighs different signals. Flesch-Kincaid and SMOG focus on syllables; Coleman-Liau and the Automated Readability Index focus on letter and word lengths; Gunning Fog focuses on long words. A 1-2 grade spread is normal. The consensus tile averages the five grade-based formulas so you get one number to act on.
Does the SMOG score work on short text?
SMOG was published for samples of at least 30 sentences. We still compute it for any input so you can compare, but if your sample is shorter, lean on Flesch-Kincaid, ARI or Coleman-Liau and treat SMOG as a rough sanity check.
Does it work on non-English text?
These formulas were calibrated for English. Word, sentence and character counts are still computed for any text, but Flesch, Flesch-Kincaid, Gunning Fog and SMOG depend on English syllable patterns and produce noisy numbers for other languages. For non-English text, treat the scores as directional only.