Does Grammarly detect AI?
Yes, in two ways. Grammarly has a free AI detector that scores text you paste in, and its Authorship feature records how a document was written: typed, pasted, or generated with AI. Here is how each works, and whether using Grammarly itself can get your writing flagged.UpdatedGrammarly's AI detector
Grammarly's AI detector is a free web tool: paste text or upload a document and it returns a percentage estimate of how much of it reads as AI-generated. Paid plans add more detail. Like every detector of this kind it estimates from patterns in finished text, so it can be wrong in both directions, and edited or mixed drafts are where it is least certain.Grammarly's Authorship, below, works differently: it doesn't guess from the finished text, it records the writing as it happens.How Grammarly Authorship works
Authorship runs through the Grammarly browser extension in Google Docs, the Grammarly desktop app in Microsoft Word, and the Grammarly editor. As you type, it tags the origin of every chunk of text: human typing, a single paste, an AI suggestion accepted from GrammarlyGO, or AI output pasted in from a third-party tool like ChatGPT.The data produces an Authorship report the writer can export as a PDF and share with an instructor or manager.This is fundamentally different from post-hoc AI detectors like GPTZero, Turnitin, or Copyleaks. Those tools analyze a finished document. Authorship watches the writing process itself, which makes it reliable for detecting paste events and less sensitive to the stylistic false positives that trip statistical detectors, including on non-native English writing.Does using Grammarly get flagged as AI?
Grammar and spelling fixes usually don't. Turnitin says that in its tests on human-written documents, corrections made by Grammarly and other grammar checkers were in most cases not flagged as AI. Text produced by Grammarly's generative features, such as drafting, paraphrasing or rewriting whole sentences, is a different matter: Turnitin says that is likely to be flagged.So accepting a comma or a spelling fix is low risk, while letting Grammarly rewrite a paragraph makes it AI-written text as far as a detector is concerned. If your school limits AI use, the same line usually applies to its policy. To see how a draft reads before you submit, paste it into Leap's free AI detector.Accuracy in practice
On direct paste detection, Authorship is essentially deterministic: it either has paste telemetry or it does not. That is high reliability by construction, not by classifier skill. Grammarly publishes no false-positive rate for paste tracking because there is nothing to be false-positive about when the data is a real keystroke log.The trade-off is coverage. Authorship only sees writing done while tracking is on, in places such as Google Docs, Microsoft Word or the Grammarly editor. A student who drafted somewhere else, or in Docs before switching tracking on, then pasted the draft in for a cleanup pass, produces a report that shows almost no typing, because the bulk of the writing happened before Authorship was watching. That can look suspicious to an instructor who does not understand the product.Grammarly's Authorship guide is clear on the limit: Authorship documents the writing process it tracked, and text it cannot trace to a source is labeled unknown.What to do about it
If a course or employer requires Authorship, the practical workflow is to turn it on where you write, in Google Docs, Microsoft Word or the Grammarly editor, and keep it on from the first draft forward. Pasting research quotes is fine: Authorship logs those as pasted text, and that is accurate. The pattern that raises questions is a long essay that arrives as a single paste with minimal typing after.If AI assistance is permitted and you want a clean Authorship report, using Grammarly's own AI suggestions instead of pasting ChatGPT output keeps the report clear, since that text is labeled as Grammarly-assisted. To review the final text before you submit, a detector that reads writing signals, such as Leap's free one, covers what paste tracking can't see. How AI detectors work explains the difference between tracking the writing process and scoring finished text.The responsible-use note
Defeating AI detection does not change the underlying integrity question. If AI help is prohibited on a specific assignment, using a humanizer to pass detection is still a policy violation, just a harder one to catch. This page exists to help writers understand the tooling, not to encourage misconduct. Know your institution's rules, and disclose AI use where required.If AI assistance is permitted and you just want to verify your final text reads naturally, run it through Leap's free AI detector first. It runs in your browser, needs no account, and shows the sentences with the strongest AI writing signals. Treat the score as a signal, not proof, and never as the only basis for an accusation.Frequently asked questions
Yes. Grammarly has a free AI detector that estimates how much of a pasted text reads as AI-generated, and since 2024 its Authorship feature tracks how a document was written: typed, pasted, or generated with AI. Basic Authorship tracking is free; paid plans add detail on text copied from AI tools and websites.
Usually not, for spelling and grammar fixes. Turnitin says its tests found that, in most cases, corrections from Grammarly and other grammar checkers weren't flagged as AI. Text that Grammarly's generative features wrote or paraphrased is likely to be flagged.
GPTZero analyzes a finished document statistically, using signals such as perplexity and burstiness, to estimate whether AI wrote it. Grammarly Authorship is a behavior tracker. It runs while you write and logs keystrokes and paste events, so it knows whether content was typed or pasted rather than inferring it after the fact.
Often, yes. Authorship tracks pasting in Google Docs, Microsoft Word and the Grammarly editor, and with clipboard access it can tell text copied from a generative AI source such as ChatGPT apart from text copied from a website. On paid plans the report shows which text came from an AI source. It only knows what happened while tracking was on: text written with Authorship switched off leaves it no data to report.
Partly. Basic Authorship tracking is free in Google Docs and Microsoft Word, with as many reports as you need showing what you typed. The AI parts, the share of text copied from an AI source and AI detection inside the report, need a paid plan such as Grammarly Pro.
Some schools have started requiring Authorship reports with submissions as a way to prove process rather than detect output. Your instructor would tell you to install Grammarly, turn on Authorship where you write (Google Docs, Microsoft Word or the Grammarly editor), and share the Authorship report alongside the final paper.
Grammarly's AI writing assistant (GrammarlyGO) is flagged in the Authorship report as Grammarly generated. The report separates human typing, pasted text, and AI-assisted rewrites, so instructors reviewing an Authorship export can see Grammarly's own contribution distinctly.
