Prompt reading level checker
Clear prompts get clearer answers. If your instructions are buried in long, clause-heavy sentences and rare vocabulary, a model is more likely to miss part of what you asked. This tool scores your prompt with the same readability formulas used for plain-language writing — Flesch-Kincaid, Gunning Fog, and Flesch Reading Ease — so you can spot and fix density before it costs you a bad response. Everything runs locally in your browser.
How it works
You paste your prompt text. The tool splits it into sentences and words, counts syllables with a vowel-group heuristic, and identifies complex (three-plus syllable) words. From those counts it computes the Flesch-Kincaid grade level, the Gunning Fog index, and the Flesch Reading Ease score, and reports your average words per sentence and complex-word count. If the estimated grade level rises above 12, it flags the prompt as likely too dense.
Tips and notes
Aim for roughly grade 8 to 12 for instructions — readable without being simplistic. The two biggest levers are sentence length and word choice: break a 40-word sentence into two, and replace “utilize” with “use,” and the scores drop quickly. The syllable counter is a heuristic, so treat results as accurate to about a grade level rather than exact. Because nothing leaves your browser, you can check sensitive or proprietary prompts here freely, then paste the simplified version into your model and compare the quality of the responses.