Free Flesch-Kincaid Readability Checker
Paste your draft and get the Flesch Reading Ease score, the Flesch-Kincaid grade and four other readability formulas, with the hardest sentences, passive voice and wordy phrases highlighted for rewriting. It runs entirely in your browser, so unpublished copy never leaves your machine.
Your text
Analysed in your browser — nothing is uploaded. Your draft is kept on this device only.
Audience
Blog posts, help pages and most landing pages: plain English, grade 8 or below.
At a glance
Scores
Improve it
Click any item to find it in the text.
Findings appear as you write.
All formulas
| Flesch Reading Ease 0–100, higher is easier. Sentence length and syllables per word. | — |
|---|---|
| Flesch-Kincaid Grade US school grade. Same inputs as Reading Ease, rescaled. | — |
| Gunning Fog Grade, weighted by words of three or more syllables. | — |
| SMOG Needs 30+ sentences; left out of the consensus. | — |
| Coleman-Liau Grade from letters per word rather than syllables. | — |
| Automated Readability Grade from characters per word and words per sentence. | — |
These formulas count sentence length and word length — nothing else. A short sentence can still be unclear, and there is no score Google rewards. Use them to find the sentences worth rewriting, not as a number to hit.
Why use the Readability Checker
Private by design
No account needed. What you type stays in your browser unless you ask for an AI suggestion or name a URL to fetch.
Sees what a crawler sees
URLs are fetched anonymously and without running JavaScript, so the result is the HTML a basic crawler gets.
Rules, not opinions
Every check is deterministic. Run the same input twice and you get the same result.
Frequently asked questions
What readability score should I aim for?
For most web copy, a Flesch Reading Ease of 60 or more, which is roughly a US grade 8 reading level. Consumer copy does better at 70 or more. Technical documentation can sit lower, because its readers expect precise terms. Pick the audience above and the tool judges your score against that range instead of a single number.
Does readability affect Google rankings?
Not directly. Google has never named a readability score as a ranking factor. Copy that is easy to read does keep people on the page and gets quoted more often, and those effects show up in the results. Treat the score as a way to find sentences worth rewriting, not as a target to optimise — and pair it with the keyword density checker to catch repetition.
Why do readability tools give different scores for the same text?
Mostly because of syllable counting. Every formula needs syllables per word, and English spelling defeats every rule-based counter somewhere. Tools also disagree on what ends a sentence: abbreviations, headings, list items. Scores within a few points of each other are measuring the same thing.
Is my text uploaded anywhere?
No. The analysis runs in a Web Worker inside your browser tab, and no request is made while you type. The draft is saved to your browser's local storage so it survives a reload. It stays on your device and is never sent to a server.
Why is the SMOG score greyed out?
SMOG was calibrated on samples of 30 sentences, and on shorter text it swings too much to be useful. Below that length the tool still shows it but leaves it out of the consensus grade.
Updated · Built by Niraj Kumar