Readability Checker
Check the readability score of any text online for free — Flesch Reading Ease, Flesch-Kincaid grade level, and sentence stats, instantly inside your browser.
What does this checker measure?
Readability scores estimate how easy a piece of text is to read, based on sentence length and word complexity. This tool calculates the Flesch Reading Ease score (0-100, higher is easier) and the Flesch-Kincaid Grade Level (the U.S. school grade needed to understand the text on a first read).
It's useful for confirming that content matches its intended audience — marketing copy usually aims for an easy, conversational level, while technical documentation can reasonably score lower.
GuideHow to use it
How the score is calculated
Both formulas use sentence count, word count, and syllable count. Flesch Reading Ease is 206.835 - 1.015 × (words/sentences) - 84.6 × (syllables/words). The Flesch-Kincaid Grade Level uses 0.39 × (words/sentences) + 11.8 × (syllables/words) - 15.59. Syllables are estimated using vowel-group counting, which is standard for this kind of tool and close to, though not perfectly identical to, a dictionary syllable count.
Features & benefits
Why this runs entirely in your browser
Draft content is often unpublished, so nothing is uploaded. Scoring runs in JavaScript locally in the tab, which means it keeps working offline once the page has loaded and nothing pasted into it persists after the tab is closed.
Common uses
Checking that landing page copy stays easy to read, matching content difficulty to a target audience's reading level, or comparing drafts before and after an edit pass.
Frequently asked questions
A few things people usually want to know before trusting the numbers.
60-70 is considered plain English, easily understood by 13-15 year olds. Scores above 80 are very easy; below 30 are best suited to college-level readers.
It estimates the U.S. school grade a reader would need to understand the text on a first read — a score of 8 means roughly an 8th-grade reading level.
By counting vowel groups per word, a standard approximation used by readability tools — it's very close to, though not always identical to, a dictionary count.
Shorten long sentences, replace complex or multi-syllable words with simpler alternatives, and break up dense paragraphs.
No. All scoring happens locally in your browser. Nothing pasted here is sent to a server, stored, or shared.