In most cases, no — correcting your own grammar and spelling is normally fine, the same way a spellchecker always has been. It usually only crosses a line if the tool rewrites your sentences and changes your meaning, or does the thinking for you.
Your department's policy is the final word, and the grey area — paraphrasing tools that reword whole passages — is where students most often get caught out.
Fixing your writing vs replacing it
There is a real and defensible difference between the two, and it's the distinction nearly every UK policy is reaching for even when the wording is clumsy.
- Editing — correcting “their/there”, catching a typo, fixing a tense, tightening a clumsy sentence you wrote. Students have done this forever, with proofreaders, friends and spellcheckers. Nobody seriously contends this is misconduct.
- Composing — feeding in a rough idea and letting a model produce polished paragraphs you didn't write. That's the output being the model's, not yours, however lightly you edit it afterwards.
The useful question isn't “did I use a tool?” but “whose sentences are these?”
The paraphrasing trap
Rewording tools — “paraphrasers”, “humanisers”, synonym swappers — are the highest-risk category. Some universities treat heavy use as misconduct in its own right, and in 2026 at least one case saw a student's use of a synonym tool recorded against them.
There's a practical reason beyond the rules: swapping words for near-synonyms tends to make academic writing worse. Precision goes first — “significant” becomes “substantial”, a term of art becomes an approximation, and a marker reads a sentence that no longer says quite what you meant. Markers notice this long before any software does.
If English isn't your first language
This is where the guidance gets genuinely unfair, and it's worth naming. Students writing in a second language have the strongest legitimate need for grammar support and face the highest false-positive risk from detectors — the Stanford figure of roughly 61% wrongly flagged is about exactly this group. Using a tool to correct your grammar is not what causes that; careful, formal, correct prose is. But it does mean keeping your drafts matters more for you than for anyone else.
More on this in our guide to writing essays in your second language.
The safest working approach
Keep the words yours. Use tools to catch mistakes, not to compose. If a suggestion changes what a sentence means rather than how it reads, reject it and fix the sentence yourself — and if your course requires a declaration of tool use, make it.
SafeGrade flags what's wrong and explains why, so you fix it in your own voice rather than accepting a rewrite. Your essay is never stored, never used for training.
Run one free scan →No card. No catch. First scan free.