There is no universal rule, but practical guidelines vary by context. For business writing, blog posts, and marketing copy, keep passive voice below 15%. For academic and scientific writing, up to 30% is generally accepted since passive is conventionally used to omit the researcher. Above 30% in any context typically produces writing that feels unclear, evasive, or bureaucratic.

No. The detector uses a carefully constructed regex pattern — a set of rules matching auxiliary verb + past participle combinations — to identify passive constructions without any AI or external NLP library. This keeps the tool entirely client-side, zero-latency, and private. Accuracy is approximately 80–90% for standard English prose. Edge cases involving highly unusual sentence structures may occasionally be missed.

Active voice is more direct, easier to process, and creates clearer cause-and-effect relationships. "The manager approved the budget" is immediately clear. "The budget was approved by the manager" requires the reader to mentally rearrange the sentence. At scale, a document with many passive sentences becomes cognitively exhausting to read. Active voice also tends to produce shorter sentences, which improves readability scores across all major formulas.

Yes — passive voice is conventional in scientific writing. Phrases like "samples were analyzed", "data were collected", and "results were recorded" are standard because scientific convention traditionally omits the researcher as the subject. Most scientific journals accept or require this style. Some modern journals (notably PLOS ONE) now encourage active voice in methods sections, but both conventions are widely accepted.

No. All analysis is performed entirely within your browser using JavaScript. Your text — whether it is a draft article, confidential report, or academic paper — is never transmitted to any server and is never stored anywhere. The tool processes everything locally in your browser tab and discards the text when you close the page.

Find the agent (who performed the action) — it is usually after "by" in passive sentences. Move the agent to the subject position at the start of the sentence, and restructure the verb to its active form. Example: "The report was written by the team" → "The team wrote the report". If there is no "by" phrase and the agent is unknown, you can either invent a plausible subject or rewrite the sentence to focus on the action differently.

It catches the most common patterns — approximately 80–90% of passive constructions in standard business and academic prose. It may miss: very unusual past participle forms, passive constructions nested inside complex clause structures, and some progressive passive forms (e.g., "is being considered" depending on sentence context). For comprehensive grammar checking including rare edge cases, a dedicated grammar tool or human editor is recommended.