Passive voice checker
Paste your writing to see every passive construction highlighted. Red marks hide who did the action; amber marks name the actor with “by…” and are the easiest to make active.
Marked up
What passive voice actually is
In an active sentence the subject does the action: Two raters coded the responses. In a passive sentence the object of the action is promoted to subject, the verb becomes a form of “be” plus a past participle, and the doer either moves into a “by” phrase or disappears: The responses were coded (by two raters).
Flip the sentence to watch the three parts swap places, then try the zombie test. Passive is a tool: it lets you put known information first and hide an actor who does not matter. It is a problem only when it hides one who does.
Active: subject → verb → object.
Questions
Is passive voice wrong in academic writing?
No. APA 7 (section 4.13) recommends active voice where possible but accepts passive when the actor is unknown or unimportant, such as “The samples were stored at −20 °C.” The problem is passive voice by habit, which hides who did what and lengthens sentences.
How does the checker detect passive voice?
It looks for a form of “be” or “get” (is, was, were, been, being, got) followed by a past participle, optionally with an adverb in between, such as “was carefully measured”. It recognises regular -ed participles and about 90 irregular ones such as written, taken and shown, and skips common adjectives like “interested” or “tired”.
What is a good percentage of passive sentences?
There is no official limit. Many writing centres suggest keeping passive sentences under about 10–20% in essays; methods sections in the sciences often run higher, and that is acceptable.
What is the zombie test?
Rebecca Johnson, a professor at the Marine Corps University, popularised the trick: if you can add “by zombies” after the verb and the sentence still makes grammatical sense, it is passive. “The survey was distributed (by zombies)” works, so it is passive.