Free browser tool

Free Readability Score Checker

Estimate Flesch Reading Ease, Flesch–Kincaid grade and Gunning Fog for English text, with long sentences to review. Local, free and no AI.

Quick answer

What readability score checker does

Readability formulas summarize surface features such as sentence length and estimated syllables per word. They can help identify dense prose, but they cannot tell whether an explanation is correct or understandable to a particular reader. This tool calculates Flesch Reading Ease, Flesch–Kincaid grade and a Gunning Fog estimate. Syllables are counted with an English spelling heuristic rather than a pronunciation dictionary.

Readability checker with sentence review and reading-level estimates – KnowledgePilot.

How to use this tool

Paste English prose or import a supported readable document.
Calculate the formula-based scores and inspect the longest sentences.
Edit for your actual reader and recalculate without treating the score as a writing grade.

Worked example

“Check the source. Read the surrounding passage.” uses short sentences and familiar words. A single sentence with several clauses can increase estimated grade level even when the explanation remains useful. Compare revisions of the same passage rather than ranking unrelated documents.

What to check before using the result

Names, abbreviations, headings and technical vocabulary can skew the scores. A short passage gives an unstable estimate; use at least ten words and preferably several complete paragraphs. Sentence boundaries are approximate, so abbreviations can be miscounted. The longest-sentence list is a prompt for review, not a command to split every long sentence. Keep precise terms and useful qualifications when editing.

Good to know

Frequently asked questions

Is this tool free and does it use AI?

It is free without an account. It uses fixed parsing rules, formatting or arithmetic in your browser, without AI or paid API calls. KnowledgePilot’s AI summarizers are separate products.

Does my text or file leave this device?

Inputs and document files are processed locally. This tool does not upload your text or files to KnowledgePilot. Optional saved drafts stay in your browser, so download a copy before clearing its data.

Can I rely on the result without checking it?

Review the worked example and limits above. The output follows the information you enter; it does not verify the source or supply missing facts. Check important details against the original material.

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Finding information is only the first step. KnowledgePilot helps you understand documents, ask questions, and verify every answer against the original source.

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