Passive Voice Detector
Paste an essay, report or paper and the detector lists every sentence that contains a form of to be followed by a past participle — the pattern behind most passive voice — and gives you the share of passive sentences in the text. It is a pattern match, not a parser, so it marks candidates for you to judge rather than rewriting anything. Free, no sign-up, and nothing is uploaded.
How to Use the Passive Voice Detector
- Paste your text. Anything from a paragraph to a full paper works. Results appear as you type, in your browser only.
- Read the four counts. Total words, total sentences, passive sentences and the passive percentage — passive sentences divided by all sentences.
- Check the rating. Up to 10% shows Excellent, above 10% and up to 20% Good, anything higher Needs Work. These bands are this tool’s rule of thumb, not a style-manual standard, so use them to compare drafts of your own.
- Go through the list. Each sentence appears with the matched words in red, such as were collected. Decide for each one: is the doer unknown, unimportant or deliberately hidden, or would the sentence be clearer if it named who acted?
What Passive Voice Is
In an active sentence the subject performs the action: The research team collected the samples. In a passive sentence the subject receives it: The samples were collected by the research team. The passive is built from a form of to be (am, is, are, was, were, be, been, being) plus a past participle (collected, written, taken), and the doer can be dropped altogether — The samples were collected. Passive voice is grammatical, not wrong; it only becomes a problem when it hides who did what or makes sentences longer than they need to be.
APA Style asks writers to use the active voice as much as possible for direct, clear and concise sentences, and to reserve the passive for cases where the recipient of the action matters more than the doer. That is why the passive is normal in a Methods section (Participants were recruited through…) and a poor default in an argument, where readers want to know who claims what.
How the Detector Decides
The text is split into sentences at each period, question mark or exclamation mark followed by a space, except after abbreviations such as Fig., Eq., Tab., e.g., et al. and Dr., which stay inside their sentence. A sentence counts as passive when a form of to be is immediately followed by a past participle: a regular word ending in -ed (four or more letters), one of about 100 common irregular participles (built, done, given, made, taken, written), or a compound of one (overtaken, rewritten). Common look-alikes such as open, often, even, red, need and unknown are not treated as participles. The first match is shown; a sentence is counted once however many it contains. Matching is case-insensitive.
| Sentence | Result | Why |
|---|---|---|
| The samples were collected by the research team. | Found | were collected fits the pattern. |
| It’s been done before. | Found | been done — the contraction itself is ignored. |
| The model was carefully tested. | Missed | carefully sits between was and tested, so the words are not adjacent. |
| This is often true. | Not flagged | often is not a participle, so is often is ignored. |
| The door is open. | Not flagged | open is an adjective, not a passive verb. |
| The students are tired. | False alarm | tired ends in -ed and is treated as a participle, although it describes a state. |
| Fig. 1 shows the trend. | One sentence | The period after Fig. does not end the sentence. |
So expect some false alarms with participial adjectives such as tired, excited or interested, and some misses where an adverb or not comes between the verb and the participle, where get replaces be (got stolen), or where an abbreviation outside the built-in list splits a sentence. The percentage is only as reliable as those limits, so read the list rather than trusting the number alone.
Worked Example
This five-sentence methods paragraph scores 3 passive sentences out of 5, or 60.0%, and rates Needs Work:
Before
The samples were collected by the research team. We analysed the data with R. The results were reviewed twice. The committee approved the proposal. The study was conducted in 2020.
Flagged
were collected; were reviewed; was conducted
After
The research team collected the samples. We analysed the data with R. Two reviewers checked the results twice. The committee approved the proposal. We conducted the study in 2020.
The rewrite scores 0.0%. Notice what the rewrite had to invent: Two reviewers was not in the original, because the passive never said who reviewed the results. Naming the actor often exposes a gap in what you know, and sometimes the right answer is to keep the passive and move on.
Which Tool Do You Need?
| If you want to… | Use |
|---|---|
| Find sentences where the subject receives the action, and the passive percentage | This Passive Voice Detector |
| Count and classify every am, is, are, was, were, be, been, being, passive or not | To Be Verb Checker |
| Find abstract nouns such as implementation and phrases such as make a decision | Nominalization Finder |
Frequently Asked Questions
- What is passive voice?
- A sentence is passive when its subject receives the action instead of performing it: The paper was written by the student rather than The student wrote the paper. It is formed with a to be verb and a past participle, and the by phrase naming the doer can be left off.
- Is passive voice always wrong in academic writing?
- No. APA Style prefers the active voice but accepts the passive when the receiver of the action is the focus, as in Samples were collected at 8 a.m. in a Methods section. Use it deliberately — when the doer is unknown, obvious or unimportant — not by habit.
- What percentage of passive voice is acceptable?
- No style manual publishes a figure. This tool rates up to 10% as Excellent and up to 20% as Good, which is a convenient rule of thumb, not a requirement. Methods sections run higher than introductions or discussions, so compare like with like.
- Why was a sentence flagged that is not passive?
- The detector matches the pattern to be plus a past participle. A participial adjective — The room is crowded, She is tired — matches too, because it looks the same as a passive verb. Decide each flagged sentence yourself.
- Why was a passive sentence not flagged?
- The pattern requires the two words to sit side by side, so was carefully tested and were not reviewed are missed. Passives built with get (got caught) and irregular participles outside the built-in list are also missed.
- How do I change a passive sentence to active voice?
- Find who or what did the action, make that the subject, and put the verb in the active form: The results were reviewed twice becomes Two reviewers checked the results twice. If you cannot name the doer, the passive may be the honest choice. The Active vs Passive Voice guide walks through more examples.
- Does the detector rewrite my sentences?
- No. It lists the sentences and the matched words; you write the replacement. Nothing is sent to a server.