Readability Checker
Analyze your text with 5 readability formulas, see sentence-by-sentence difficulty, and check if you hit your target grade level — all in real time.
Quick Answer
Readability is measured using formulas like Flesch-Kincaid (based on average sentence length and syllables per word), Gunning Fog, Coleman-Liau, SMOG, and Automated Readability Index. Most web content should target a 6th-8th grade reading level (Flesch-Kincaid score of 60-70) for maximum accessibility. The average American reads at a 7th-8th grade level.
About This Tool
The Readability Checker analyzes your text using five established readability formulas to give you a comprehensive view of how easy or difficult your writing is to understand. Unlike tools that rely on a single metric, this tool cross-references multiple formulas so you can see a more reliable picture of your text's reading level.
The five formulas included are: Flesch Reading Ease (a 0-100 scale where higher means easier), Flesch-Kincaid Grade Level (estimates the U.S. school grade needed), Gunning Fog Index (estimates years of formal education needed), Coleman-Liau Index (uses character counts rather than syllables for better accuracy with technical text), and SMOG Index (considered the gold standard for health literacy assessment).
The sentence-by-sentence color coding is a standout feature that helps you identify exactly which sentences are dragging up your reading level. Green sentences are easy to read, yellow sentences are moderate, and red sentences are difficult. This makes editing for readability targeted and efficient — you know exactly where to focus your revision efforts.
The grade level target selector lets you set a goal (5th grade, 8th grade, 10th grade, or college) and instantly see whether your text meets that target. Most successful web content is written at an 8th grade level. Health content for the general public should target 5th-6th grade. Everything runs locally in your browser — no data is sent to any server.