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Does using Grammarly make your essay look AI-generated?

Updated 30 August 2026 · 4 min read
Short answer

Fixing errors doesn't. Accepting rewrites can. Correcting a typo or a tense changes almost nothing about how predictable your prose is. Letting a tool rephrase whole sentences pushes them towards the most conventional way of saying something — which is exactly what a detector scores as machine-like.

The line is between fixing mistakes you made and replacing sentences you wrote.

Why the two are different

A detector measures how expected each word is, given the words before it. Changing “their” to “there” doesn't move that needle: one word, already predictable either way. But a suggestion that restructures a clumsy sentence into a smooth one is, by design, choosing the most standard available phrasing — and standard phrasing is low-surprise text.

Do that across forty sentences and the aggregate effect is real. Not because a tool was involved, but because the prose has been sanded towards the average.

A rough rule

If a suggestion changes how you said it, it nudges your score. If it changes whether it was correct, it doesn't. Accept the second freely; think about the first.

Is it against the rules?

Usually not for error correction — that's been ordinary practice for as long as spellcheckers have existed, and most UK policies say so explicitly. Rewriting is greyer, and paraphrasing tools that reword whole passages are the highest-risk category: some universities treat heavy use as misconduct in its own right. The full picture is in is using AI to fix my grammar against the rules?

Worth noting separately: many editing tools now bundle a generative assistant alongside the checker. Those are different features with different rules, and “I only used Grammarly” doesn't distinguish between them if you used both.

The other cost of accepting everything

Marks. Rewrite suggestions optimise for smoothness, not for precision, and academic writing lives on precision. A suggestion will happily swap a term of art for a near-synonym, soften a claim you meant to make firmly, or flatten a distinction your argument depends on. Markers notice that long before software does — and unlike a detector score, it costs you directly.

How to use one sensibly

If you're a second-language writer, this needs saying: grammar support isn't what puts you at risk. Careful correct prose is — see why detectors flag non-native speakers more. Keep using the help; keep the drafts.

A check that hands the pen back to you

SafeGrade flags what's wrong and explains why, so you fix it in your own voice rather than accepting a rewrite. Never stored, never used for training.

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Sources: Higher Education Policy Institute — AI detectors and the fairness gap (August 2026); HEPI — Catching the wrong students (July 2026); Stanford study on AI-detector false positives for non-native English speakers; Office of the Independent Adjudicator case decisions, 2026. SafeGrade reports third-party research and does not publish its own detection-accuracy figures.