Readability Checker

Paste a draft to see its Flesch-Kincaid grade level, reading ease, and hard-sentence and adverb highlights.

Readability checker — Flesch-Kincaid grade level, reading ease & hard-sentence highlighter Readability Checker helps writers, students, and editors see how easy a draft is to read — before it goes out the door — without sending the draft anywhere. Paste your text in, and the popup instantly shows: - Flesch-Kincaid Grade Level and Flesch Reading Ease, the two standard published readability scores (the same formulas behind most word processors and readability tools). - Hard-sentence highlighting: sentences that are long enough to be hard to follow are flagged, Hemingway-style. - Adverb highlighting: "-ly" words are flagged as a nudge to consider a stronger verb instead. PRIVATE BY DESIGN This is a paste-mode tool: it never reads the active tab or any page content, requests no host permissions, and injects no scripts. Your draft never leaves your browser. This extension collects no data of any kind — no analytics, no tracking, no telemetry. The only network traffic it ever makes is a purchase-verification check with ExtensionPay if you choose to upgrade. ESTIMATES, NOT A GRAMMAR PARSER Flesch-Kincaid Grade Level and Reading Ease are the standard published formulas and are computed exactly. Syllable counting, hard-sentence thresholds, adverb detection, and (premium) passive-voice detection are heuristic estimates — not a dictionary lookup or a full grammar parser — and can occasionally over- or under-flag a word or sentence, the same tradeoff every lightweight readability tool makes. FREE, AND GENUINELY USEFUL - Grade level and reading ease, computed live as you type. - Hard-sentence highlighting (yellow/red, by sentence length). - Adverb highlighting. - Always-visible word, sentence, hard-sentence, and adverb counts. PREMIUM ($5 one-time) Built for anyone editing drafts seriously: - Passive-voice highlighting, layered into the same highlighted view. - Per-paragraph breakdown: grade level and word count for each paragraph separately, so you can spot the one dense paragraph dragging down an otherwise-easy piece. - Target-grade meter: tell it your target grade level and see how far off your draft is. - Local draft history: save named snapshots of a draft (with its scores) and reload them later — stored only on your device. - Annotated export: download a plain-text/Markdown report with the scores and inline annotations (bold = passive voice, italic = adverb, tags = hard sentences). No subscription, no account required — pay once, keep the features.