Readability Checker

Readability Checker is a free online tool that analyses your text and calculates multiple readability scores to show how easy or difficult it is to read. Paste any text and instantly get scores including Flesch Reading Ease, Flesch-Kincaid Grade Level, Gunning Fog Index, and SMOG Index, along with statistics on sentence length, word length, and syllable count.

Readability is the measure of how easy a piece of text is to understand for a given audience. It is determined by factors including average sentence length, average word length, syllable count per word, and the use of familiar versus technical vocabulary. Text that is too complex for its intended audience leads to drop-offs, misunderstanding, and low engagement. Text that is too simple for a professional or academic audience can feel condescending.

The Flesch Reading Ease score (0–100) is the most widely used readability metric. A score of 70–80 is considered easy to read, roughly equivalent to a 7th-grade level — the standard target for general-audience web content. A score of 60–70 is fairly easy (8th–9th grade). Below 30 is very difficult, typical of academic papers and legal documents. Most web content should target 60–70+ to be accessible to the broadest possible audience.

The Flesch-Kincaid Grade Level converts the Reading Ease score into a US school grade level. Grade 8 (13–14 year olds) is the typical target for online content. Grammarly targets Grade 8, and most major news publications write at Grade 6–8. For technical documentation targeting experts, Grade 12+ is acceptable. For consumer-facing content, the lower the better.

Improving readability is mostly about structure: shorten long sentences by splitting at conjunctions, replace multi-syllable jargon with shorter plain-English alternatives, use active voice instead of passive, break up long paragraphs into shorter ones, and use bullet points for lists. These changes improve readability scores and, more importantly, improve actual comprehension and engagement.