The short answer
Partly. In Scribbr's own 30-text test, its premium AI detector was right 84% of the time and the free version 78%, with no human text flagged. A small independent test found the free version caught 4 of 9 AI samples. Plagino has not benchmarked Scribbr, so treat its score as a signal, not proof.
How accurate is Scribbr's AI detector?
Scribbr is unusually open about the limits of its detector, and the evidence it publishes is modest. The best figure available is Scribbr's own: 84% overall accuracy for the premium detector and 78% for the free one, on a small test set Scribbr built itself.
Plagino has not benchmarked Scribbr. Our March 2026 benchmark covered seven detectors and Scribbr was not one of them. The figures below are Scribbr's own claims or third-party tests, and we label each one.
What Scribbr's own test found
Scribbr's best AI detector research (published 22 April 2026) ran 12 detectors on 30 texts, each 1,000 to 1,500 characters long. There were five texts in each of six groups: human-written, GPT-3.5, GPT-4, human text mixed with GPT-3.5, GPT-3.5 text paraphrased with QuillBot, and human text paraphrased with QuillBot.
Scribbr's premium detector scored 84% and its free detector 78%, the highest premium and joint-highest free scores in that test. Scribbr says neither labelled any of its human texts as AI, and both detected every GPT-3.5 and GPT-4 text. Mixed and paraphrased AI text was much harder: the premium tool caught 60% of those, the free tool 50%.
Keep the scale in mind. Five fully human texts cannot establish a false positive rate, and GPT-3.5 and GPT-4 are older than the models most students use in 2026. Scribbr also wrote and scored the test of its own product. Its detector page quotes a different free-tool figure ("68% in the best free tool") from the article it links to, so the numbers have shifted between updates.
What independent testing found
In a January 2026 comparison, Pangram Labs ran Scribbr's free detector on nine roughly 1,000-word AI samples (from GPT-4o, Gemini 2.0 and Claude 3.7 Sonnet) and three human texts. Scribbr passed all three human texts and flagged 4 of the 9 AI samples at Pangram's 75% threshold.
Pangram sells a competing detector and used twelve samples, so this is an indication, not a rate. It is consistent with Scribbr's own warning that the free version detects older models "with average accuracy".
Is Scribbr's AI detector powered by Turnitin?
No. This is a common mix-up. Scribbr's plagiarism checker uses Turnitin technology: Turnitin's own partner story quotes Scribbr saying it included "Turnitin technology in the Scribbr platform". Scribbr's AI detector is a separate product. Scribbr's plagiarism page says the add-on AI detector "is powered by Scribbr's proprietary software".
So a Scribbr plagiarism report can come close to a Turnitin similarity report, but a Scribbr AI score tells you nothing about what Turnitin's AI detector will say. Even on plagiarism, Scribbr notes that universities may check work against private student-paper databases that Scribbr cannot access. For more on Turnitin's detector, see does Turnitin detect AI.
How do Plagino and Scribbr compare side by side?
Scribbr charges per document and is strongest on plagiarism. Plagino is a monthly plan that puts AI detection and source matching in one report. Here is how they line up as of October 2026.
| Plagino | Scribbr | |
|---|---|---|
| AI docs caught | 97.4% in Plagino's March 2026 benchmark (n=500) | Not tested by Plagino. Scribbr's own test: 84% overall accuracy (premium), 78% (free), on 30 texts |
| Human docs wrongly flagged | 0.8% in the same benchmark (n=500) | Not tested by Plagino. None of 5 human texts in Scribbr's own test |
| Free tier | 3 scans/month, no card | Unlimited AI checks up to 1,200 words each, with ads |
| Paid price | Pro: $19/month for 20 scans a day | Per document: $19.95 (to 7,499 words), $29.95 (to 49,999), $39.95 (50,000+), premium AI check included |
| Plagiarism check against | CORE open-access research index | Turnitin-powered: 99.3 billion web pages and 8 million publications; no private student-paper databases |
| Input | Upload a .docx file | Paste text (free AI); Word or PDF upload (plagiarism check) |
| AI report detail | Sentence-level highlights in a PDF report | Paragraph-level feedback with AI-generated, AI-refined and human labels |
Detection rate and false positives
In Plagino's benchmark, run in March 2026 on 500 AI-written documents from GPT-4o, Claude and Gemini (some lightly edited by people), Plagino flagged 97.4% (95% interval roughly 95.6% to 98.5%). Turnitin flagged more, at 98.2%. On 500 human-written documents, Plagino wrongly flagged 0.8% (roughly 0.3% to 2.0%), the lowest of the seven tools, against Turnitin's 1.4%.
Scribbr's 84% is an overall accuracy across mixed text types, not a detection rate on unedited AI essays, so the two numbers do not compare directly. Its clean result on human text is encouraging but rests on five documents. Any detector can misread formal or second-language writing: a 2023 Stanford study found several detectors misclassified more than half of the TOEFL essays it tested as AI-written. A 2023 study of 14 tools by Weber-Wulff and colleagues concluded that detection tools are "neither accurate nor reliable" and lean towards calling AI text human. Our guide to AI detector false positives covers what to do if you are flagged.
Privacy and data retention
Scribbr's AI detector page says "we do not store or share your data". For the plagiarism checker, Scribbr says submissions "will never be added to our content database", and its storage FAQ says you can delete your documents from its server once you have your report.
Plagino keeps reports in your own account. Whichever tool you use, a report is a prompt to review the writing, not evidence of misconduct.
Where Scribbr is the better choice
For one high-stakes plagiarism check, such as a thesis or dissertation, Scribbr is the stronger choice. Its checker uses Turnitin technology and searches billions of web pages and millions of publications. Plagino only searches open-access research through CORE, and does not search the open web or paywalled journals.
Scribbr's free AI detector also suits a quick check of a short passage. It needs no account, has no monthly cap, and takes pasted text. Plagino's free plan allows 3 scans a month and needs a .docx file.
If you only check a few long documents a year, paying per document can work out cheaper than any monthly plan. And Scribbr's AI-refined label is useful if you used a grammar or paraphrasing tool on your own writing and want to see how that reads.
Where Plagino is the better choice
Plagino fits regular checking of essays across a term. Pro costs $19 a month for 20 scans a day, and every scan returns AI highlights at sentence level and matched academic sources in one PDF report. Scribbr's free tool gives paragraph-level feedback, and its premium AI check comes only with a paid plagiarism check per document.
Plagino also publishes a document-level false positive rate from 500 human-written documents, with confidence intervals. If being wrongly flagged is your main worry, that is the number to compare. You can try Plagino's AI detector on a draft for free.
Test conditions and limitations of this comparison
Plagino's figures come from one benchmark run in March 2026: 1,000 documents (500 AI-written, 500 human-written), each tool used through its own web app on default settings, and scored on whether a document was flagged at all. The 95% intervals are Wilson intervals on 500 documents per rate. Your own results will differ, and a different corpus could rank the tools differently. See the full benchmark method.
Scribbr was not in that run. Scribbr's own test used 30 short texts and older GPT models and was run by the vendor; Pangram's used twelve samples and comes from a competitor. None of these figures is directly comparable with another. Prices and features were checked on 3 October 2026.
Comparing other tools? See Plagino vs Grammarly, Plagino vs Winston AI and Plagino vs Originality.ai.
Frequently asked questions
Is Scribbr's AI detector accurate?
Moderately. In Scribbr's own test of 30 texts, its premium detector was right 84% of the time and its free detector 78%, with no human texts flagged. A small independent test by Pangram Labs found the free version caught 4 of 9 AI samples. Scribbr says no AI detector can guarantee 100% accuracy.
Is Scribbr's AI detector free?
Yes. The free version allows unlimited checks of up to 1,200 words each without an account. The premium AI detector, which Scribbr says is more accurate and can detect GPT-4, comes free with a premium plagiarism check, priced from $19.95 per document.
Does Scribbr use Turnitin for AI detection?
No. Scribbr's plagiarism checker uses Turnitin technology, but Scribbr says its AI detector runs on its own proprietary software. A Scribbr AI score will not predict a Turnitin AI score.
Does Scribbr store the text I check?
Scribbr says its AI detector does not store or share your data. For the plagiarism checker, Scribbr says submissions are never added to its content database and that you can delete your documents after receiving your report.
What languages does Scribbr's AI detector support?
Scribbr's AI detector page lists English, Spanish, German and French, and its FAQ also lists Dutch for the premium add-on. Check a non-English result with extra care, since Scribbr does not publish accuracy figures by language.
Has Plagino tested Scribbr's AI detector?
Not yet. Scribbr was not part of Plagino's March 2026 benchmark. This page uses Scribbr's own published test and third-party results instead, and labels each one.