Estimate English Flesch-Kincaid grade, reading ease and an approximate Gunning Fog index locally. View word and sentence counts without API calls.
Use this free browser tool for a focused check of your text. Start with the fictional sample to understand the output, then analyze your own input and review the stated limits.
How to use
Paste English prose and choose Analyze. The report shows words, sentences, character count, average sentence length and estimated syllables. Non-Latin or mixed-script input receives counts but no English grade scores. Latin-script language cannot be detected automatically: use English only.
How it works
Flesch-Kincaid = 0.39 × words/sentences + 11.8 × syllables/words − 15.59. Reading Ease = 206.835 − 1.015 × words/sentences − 84.6 × syllables/words. Fog approximation = 0.4 × (words/sentences + 100 × complex words/words).
Limits and review
Syllables use a transparent vowel-group heuristic with a small exception list, not a pronunciation dictionary. The Fog proxy counts every word with at least three estimated syllables; proper-name, compound and inflection exclusions are not applied. Therefore it is explicitly approximate.
Example and results
The short sample demonstrates the controls. For a useful assessment, use a representative passage of at least 100 words. Abbreviations, decimals, bullet fragments and unusual punctuation can change sentence counts. Scores are not clamped and can fall outside familiar ranges.
Practical guidance
A US grade-level estimate describes linguistic complexity, not a student grade, accuracy, argument quality or guaranteed reader comprehension. Review terminology, organization and the intended audience as well as the numeric result. Hindi text is not scored with English formulas.
Frequently asked questions
Does it require an API?
No. This tool processes input locally in JavaScript without an external service.
Is input saved?
The tool keeps no input history or server copy. Copying places the result in your clipboard.
What happens when input changes?
The old result clears. Analyze again to generate output for the current input.
Is the result a final decision?
Syllables use a transparent vowel-group heuristic with a small exception list, not a pronunciation dictionary. The Fog proxy counts every word with at least three estimated syllables; proper-name, compound and inflection exclusions are not applied. Therefore it is explicitly approximate.