- How accurate is the detector?
- About 85% on typical English prose. It's a heuristic — two lists (forms of 'be' and irregular past participles) plus two suffix rules (-ed and -en) — not a grammar engine. It catches the most common passive shapes and misses the rest. Use it for first-draft editing, not as a final-pass grammar check. If you need 100% accuracy, a human edit or a full-syntax parser is the only way.
- What does it miss?
- Mainly two things. First, 'got + past participle' passives — 'the cake got eaten' is passive, but the detector only looks for forms of 'be'. Second, agentless or Latin-derived passives that don't use the standard 'be + pp' shape ('a discussion ensued', 'the door stood open'). It also can't detect implied passive in fragments without a verb. The trade-off is speed and clarity: a heuristic that runs instantly in your browser, with rules you can read in a paragraph.
- What does it falsely flag?
- The biggest false positive is the -ed adjective: 'He was very tired' isn't passive — 'tired' is an adjective there, not a past participle of a transitive verb. The heuristic can't distinguish. Similarly, 'The cake is delicious' is fine, but 'The cake is gone' may flag because 'gone' looks like a past participle in irregular form. If a flagged phrase reads naturally in active terms ('Tom tired'? 'Tom went'?), it's probably the false-positive case — ignore it.
- Why does the 10% threshold matter?
- It's a soft target from major style guides — Strunk & White's Elements of Style, the AP Stylebook, the Economist Style Guide all push writers toward active voice as the default. Passive isn't wrong; it's overused. Sentences in active voice name the actor first, which is usually what readers care about. Passive is the right choice when you genuinely want to hide or de-emphasize the actor (scientific writing, diplomatic prose, breaking-news headlines about ongoing investigations). The 10% target leaves room for those legitimate uses.
- When SHOULD I use passive voice?
- Three good cases: (1) the actor is unknown — 'The window was broken last night.' (2) The actor is irrelevant or generic — 'Reservations are accepted online.' (3) You want to put the object first for emphasis or topic continuity — 'The Mona Lisa was painted by Leonardo' if the paragraph is about the Mona Lisa, not Leonardo. Used deliberately, passive is a tool. Used by accident, it's vague writing.
- How do I rewrite a passive sentence?
- Flip subject and object. 'The report was written by the committee' becomes 'The committee wrote the report.' If the original doesn't name an actor ('Mistakes were made'), you have to invent one — and that's usually the point: passive voice often hides accountability. 'The team made mistakes.' 'I made mistakes.' Naming the actor makes the writing stronger.
- Does the tool save my text?
- No. Everything happens in your browser via JavaScript. The detector never sends your text to a server, never logs it, never stores it. Close the tab and your input is gone. The page works offline once it's loaded.
- Can I paste a whole essay?
- Yes, up to about 200,000 characters — roughly 30,000 words or 60 single-spaced pages. The matcher runs in milliseconds on text that size. Past 200,000 characters the highlighting can get sluggish on older devices; the tool will show a gentle warning and stop processing. For very long documents, paste a section at a time.
