⚡ The short answer
Every AI detector uses its own model, trained on its own data. The same essay can score 0% on one and 80% on another. None of the free detectors is Turnitin, and none of them can tell you what Turnitin will say.
If your university uses Turnitin (almost every Malaysian university does), the only score that decides anything is Turnitin's AI writing %. A free detector is fine for a rough first look; for the real number you need a Turnitin AI report.
📊 Popular AI detectors compared
| Detector | Free to use? | What it is | Same score as Turnitin? |
|---|---|---|---|
| Turnitin AI | No — university only | The detector built into Turnitin, the system your lecturer uses | Yes — it is the one |
| GPTZero | Free tier with limits; paid plans | Independent AI detector, supports several languages | No |
| ZeroGPT | Yes (with limits) | Free web AI detector | No |
| QuillBot AI Detector | Yes (with limits) | Detector from the QuillBot paraphrasing tool | No |
| Grammarly AI Detector | Yes (with limits) | Detector inside Grammarly | No |
| Scribbr AI Detector | Free tier; paid premium | Detector from the Scribbr academic site | No |
| Winston AI | Trial; paid | Paid AI and plagiarism detector | No |
Limits and plans change often; check each tool's own site. The last column does not change: only Turnitin produces a Turnitin score.
🧩 Why the scores never match
- Different models. Each detector learned from different human and AI text, so they flag different sentences.
- Different thresholds. Turnitin does not show an exact figure between 1% and 19% — it shows *% because low scores are less reliable. Free tools usually print any number.
- Different languages. Turnitin's AI detector only covers English, Spanish and Japanese. A Bahasa Melayu essay gets no Turnitin AI score at all, while some free tools will still guess.
- Length limits. Turnitin needs at least 300 words of prose for an AI score. Short pastes into free tools are much less reliable.
- Paraphrasers. Turnitin also flags text that looks AI-generated then run through a paraphrasing tool — something most free checkers do not report separately.
🗺️ Which one should you use?
- English assignment, university uses Turnitin → Turnitin AI + Plagiarism. It is the score that counts.
- Bahasa Melayu or Arabic assignment → Turnitin cannot score it. Use the GPTZero AI checker (pay per file, no subscription).
- Just curious / very early draft → any free detector is fine as a rough signal.
- Your own writing was flagged → rewrite the flagged parts in your own words, or try the AI Humanizer on them, then re-check on Turnitin.
❓ FAQ
Is ZeroGPT the same as Turnitin?
No. ZeroGPT is an independent free detector with its own model. Its score often differs a lot from Turnitin's AI writing score.
Is GPTZero accurate compared to Turnitin?
GPTZero and Turnitin use different models and frequently disagree on the same text. GPTZero is useful for languages Turnitin does not support, such as Bahasa Melayu, but it cannot predict a Turnitin score.
Can I check Turnitin AI detection myself?
Not with a personal account, because Turnitin only licenses universities. You can get a Turnitin AI writing report through Coolsbox for RM6.99, together with the similarity report.
Why does Turnitin show *% instead of a number?
Turnitin hides scores between 1% and 19% and shows *% instead, because it considers low scores less reliable and more likely to be false positives.
Does Turnitin detect AI in Bahasa Melayu?
No. Turnitin's AI writing detection supports English, Spanish and Japanese only. For Malay, use a GPTZero check instead.
📚 Related
Turnitin Check · Turnitin AI + Plagiarism · Turnitin price · AI detectors vs Turnitin · Free Turnitin checker? · How long does Turnitin take? · Reduce Similarity · AI Humanizer · APA citation generator · By university