Analyze your text's readability using multiple standard formulas: Flesch-Kincaid Grade Level, Flesch Reading Ease, Gunning Fog Index, Coleman-Liau Index, SMOG Index, and Automated Readability Index. Get grade-level estimates and actionable suggestions to make your writing clearer.
Workspace
Use the tool below. Your inputs stay local when the tool supports browser-only processing.
Last reviewed: · Testing methodology
Workflow
Paste any text into the readability score checker input. The tool works with any length from a single paragraph to full articles, automatically analyzing sentence length, syllable count, and word complexity for accurate readability assessment.
The readability score checker displays Flesch-Kincaid Grade Level, Flesch Reading Ease, Gunning Fog Index, Coleman-Liau Index, SMOG Index, and Automated Readability Index side by side for comprehensive text analysis.
Each readability score checker result includes a grade-level interpretation and suggestions for improvement. Lower grade levels indicate easier-to-read text, making this tool valuable for writers targeting specific audience reading levels.
The component estimates syllables and sentence length, then applies standard readability arithmetic to the supplied English text.
Use it to compare versions for a target audience. Add punctuation and enough prose before interpreting the score.
Use editorial review and audience testing for comprehension, tone, accessibility, domain vocabulary, and factual quality.
| Option | Best for | Trade-off |
|---|---|---|
| This browser tool | Quick, private, one-off work | Limited by browser memory and the documented feature set |
| Desktop or command-line tool | Batch jobs and repeatable automation | Requires installation and setup |
Reviewed by the Free Online Tools Nest Team on 2026-08-26. The interface, output path, and documented limitations were checked against the current implementation. See our testing methodology for the review process.
Read the testing methodologyA Flesch-Kincaid grade level between 6 and 8 is recommended for most web content, as this targets a broad audience. The readability score checker helps you verify your content is accessible to readers with at least a middle school reading level.
The Gunning Fog Index is calculated by measuring average sentence length and the percentage of complex words (three or more syllables) in your text. The readability score checker applies this formula along with five other common readability metrics for a complete analysis.