Free Text Readability Analyzer
Updated September 2026
Analyze text readability with 3 real formulas — Flesch Reading Ease, Flesch-Kincaid Grade, and Gunning Fog — plus word/sentence stats and reading time. Free, runs in your browser.
Productivity tools should accelerate your work, not slow it down. The Readability Analyzer is built for speed and simplicity so you stay in flow.
Analyze text readability with 3 real formulas — Flesch Reading Ease, Flesch-Kincaid Grade, and Gunning Fog — plus word/sentence stats and reading time. Free, runs in your browser. Results are immediate — no waiting, no loading screens, no account required.
Who uses the Readability Analyzer?
- Government and nonprofit writers checking whether public-facing content meets plain-language grade-level targets.
- UX writers spot-checking onboarding copy and error messages for reading-level appropriateness.
- Content strategists getting a quick word-count and reading-time estimate alongside readability scores.
Common uses and search terms
The Readability Analyzer is frequently used for: readability, reading level, text analysis, flesch kincaid. Whether you need a quick result or are working through a longer project, the tool handles all common variations without any configuration.
Why use Allio Tools's Readability Analyzer?
Everything runs locally in your browser. No data is sent to a server, logged, or stored anywhere. The tool is completely free with no usage limits, no premium tiers, and no account required. Available in 11 languages and optimised for all screen sizes, the Readability Analyzer works on desktop, tablet, and mobile with no app download needed.
See also:Grammar Checker · Pomodoro Timer · Writing Prompt Generator
How the Readability Analyzer works
Paste your text into the input area.
Click Analyze to compute readability scores and text statistics.
Review the Flesch Reading Ease score, Flesch-Kincaid Grade level, Gunning Fog index, and an overall reading-level label (Elementary through Graduate).
Review word count, sentence count, average words per sentence, unique-vocabulary percentage, and estimated reading time.
Tips & tricks
- Only 3 formulas are actually computed (Flesch Reading Ease, Flesch-Kincaid Grade, Gunning Fog) — don't expect SMOG, Coleman-Liau, ARI, or Dale-Chall scores, they aren't calculated here.
- There's no sentence-level highlighting or a "Simplify" rewrite feature — results are whole-text aggregate stats only, and there's no AI involved at all despite "readability analyzer" sometimes implying AI assistance.
- The syllable count uses a simple vowel-group heuristic, which is generally accurate for English but can misjudge unusual words — treat the grade-level scores as a good estimate, not an exact measurement.
- The reading-level label (Elementary/Middle School/High School/College/Graduate) is derived directly from the Flesch-Kincaid Grade number using fixed cutoffs.
Frequently Asked Questions
How many readability formulas does this tool actually calculate?
Three: Flesch Reading Ease, Flesch-Kincaid Grade Level, and Gunning Fog Index. It does not calculate SMOG, Coleman-Liau, Dale-Chall, or ARI, despite those sometimes being mentioned alongside readability tools generally.
Does this tool give AI-powered rewriting suggestions?
No — there's no AI model or API call anywhere in this tool. It's pure client-side arithmetic on your pasted text (word/sentence/syllable counts feeding the three formulas above). There's no "Simplify" button and no rewrite suggestions of any kind.
Does it highlight overly long sentences, complex vocabulary, or passive voice in my text?
No — the output is a set of aggregate statistics and scores for the whole text, not sentence-level or word-level highlighting. It doesn't flag individual long sentences, individual complex words, or detect passive voice.
How is readability analysis different from grammar checking?
Grammar checking catches errors (incorrect usage, spelling mistakes). Readability analysis measures how easy the text is to understand — sentence length, vocabulary complexity, and structure — regardless of grammatical correctness.
What Flesch-Kincaid grade level should business content target?
Business communications: Grade 7–9. Marketing copy: Grade 6–8. Legal documents (required to simplify): Grade 8–10. Academic papers: Grade 12+. The lower the grade level, the more accessible the content is.
Is my data safe when using the Readability Analyzer?
Completely safe. The Readability Analyzer processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.
Does the Readability Analyzer save my work automatically?
The Readability Analyzer operates entirely in your current browser session. Your input is not saved to any server. Use your browser's bookmark or your device's clipboard to preserve results between sessions.
Does the Readability Analyzer remember my previous inputs?
By default, the Readability Analyzer starts fresh each session. Allio Tools Pro users have session history saved locally in the browser. No input data is transmitted to or stored on any server in either case.
Works with ChatGPT, Claude, Cursor, GitHub Copilot, VS Code, Poe and more — 106+ tools, zero data collection.