Is Grammarly AI?
By Sourabh Singh30 September 20265 min read
Grammar fixes: no. Rewrites and generated text: yes. The difference is whether a language model wrote the words.
Grammarly uses AI, but most of what it does will not make your writing look AI-generated. Spelling, grammar and punctuation corrections change a few characters of text you wrote yourself, and Turnitin says its detector is not tuned to target those edits. Grammarly's generative features are different: when GrammarlyGO rewrites, paraphrases or drafts text, a language model produced those sentences, and Turnitin says that output is likely to be flagged.
Which Grammarly features can get flagged
| Grammarly feature | Who wrote the words | Risk of an AI flag |
|---|---|---|
| Spelling and grammar fixes | You | Very low |
| Punctuation and clarity suggestions | Mostly you | Low |
| Tone suggestions (single words) | Mostly you | Low |
| Rewrite a sentence or paragraph | The AI | High |
| Paraphrase or shorten | The AI | High |
| Generate a draft from a prompt | The AI | High |
The rule of thumb: if you accepted a suggestion that replaced a whole sentence, treat that sentence as AI-written. If you accepted a fix to a comma or a misspelling, it is still your writing.
Why rewrites get flagged
AI detectors look for the statistical shape of language-model text: very predictable word choices, even sentence rhythm and stock connecting phrases. A rewrite from GrammarlyGO has that shape because a language model produced it, even if the idea was yours. A spelling fix does not change the shape of your sentence at all.
How to use Grammarly without risk
- Accept spelling, grammar and punctuation fixes freely.
- Reject whole-sentence rewrites, or retype the idea in your own words.
- Turn on Grammarly Authorship before you start writing if your school allows it: it records how the document was written, which is useful evidence if you are ever questioned.
- Run the final draft through an AI detector that shows you which sentences are flagged, then rewrite those yourself.
See which sentences read as AI before you submit.
Check your draftCommon questions
Its spelling and grammar corrections generally do not. Its generative features, rewriting, paraphrasing and drafting text, do, because a language model writes those words.
Turnitin says its detector is not tuned to flag Grammarly's spelling, grammar and punctuation edits. Text rewritten or generated by GrammarlyGO is likely to be flagged.
It depends on your school's policy. Many allow grammar checking but not AI-generated or AI-rewritten text. Check your syllabus, and keep an Authorship report if you use Grammarly heavily.
Grammarly has its own AI detector, but it measures something different from Turnitin. A low score in one tool does not guarantee a low score in another.
