Winston AI vs Turnitin: the 14 fields and the study results side by side
Turnitin carries 5 study records in the index and Winston AI carries 2, and one record tested both tools on the same documents: Weber-Wulff 2023, where Turnitin classified 41 of 54 documents correctly and Winston AI 36 of 54, with 0 false accusations in 18 human-written documents for each (arXiv 2306.15666, Tables 7 and 9, read 8 November 2026). The two cards are read side by side below on the same 14 fields, with the vendor's wording and the page it came from, so the comparison rests on what each company publishes and what outside researchers measured.
Updated Fields checked 8 November 2026
Short answer
Winston AI is sold to individuals and teams from $18 a month with a 14-day trial and a public API; Turnitin's AI writing detection has no public price, no free tier and no API, and is licensed to institutions through Turnitin Originality (gowinston.ai/pricing, guides.turnitin.com, read 8 November 2026). In the one shared study, Weber-Wulff 2023, Turnitin ranked first of 14 tools with 41 of 54 documents correct and Winston AI fifth with 36 of 54; both recorded 0 false accusations in 18 human documents, and Turnitin missed 10 of 36 AI documents against Winston AI's 12 (arXiv 2306.15666, Tables 7, 9 and 10). Winston AI states 11 languages and text, image and handwriting checks; Turnitin states 7 languages and text only, with a 300-word minimum. No detector score should be the only evidence in a misconduct or hiring decision.
How do Winston AI and Turnitin compare on the 14 fields?
| Field | Winston AI | Turnitin |
|---|---|---|
| 1. Name, vendor, official domain | Winston AI, Winston AI inc., gowinston.ai | Turnitin AI writing detection, Turnitin, LLC, turnitin.com |
| 2. Modalities detected | text, image, handwriting (OCR) | text |
| 3. Generators covered | ChatGPT, Claude, Google Gemini, LLaMA, "many others"; images from Midjourney, DALL-E, Stable Diffusion, Nano Banana, ChatGPT Image, Adobe Firefly | 33 named models from Amazon Nova 2 Lite and Claude-3-Haiku to GPT-5.4-pro, Grok-4.1, Llama-4-Maverick-17b and Mistral-large-3; Spanish model GPT-3.5 and GPT-4; Japanese model GPT-4 (0613), GPT-4o, GPT-4o-mini |
| 4. Languages supported | 11: English, French, Spanish, Portuguese, German, Dutch, Polish, Italian, Indonesian, Romanian, Chinese (Simplified) | 7: English, Spanish, Japanese, Modern Arabic, Dutch, German, Turkish |
| 5. Input limits | Up to 200,000 characters per scan on Essential, Advanced and Elite (Free row blank); unlimited scans per hour on paid plans; paste or upload .docx, .png and .jpg; file size not published | At least 300 words of prose in a long-form format and no more than 30,000 words; file under 100 MB; .docx, .pdf, .txt, .rtf; lists, headers, references, tables, formulas and code excluded from scoring |
| 6. Free tier | Free plan at $0 a month with 2,000 credits for a 14-day trial, not recurring; API registration gives 2,500 credits | None: AI writing detection is only available to customers that license Turnitin Originality, or the AI writing add-on for iThenticate 2.0 |
| 7. Paid plans | Essential $18 a month (100,000 credits), Advanced $29 (200,000 credits, 5 team members), Elite $49 (500,000 credits, unlimited members); annual $60, $96 and $156 a year; a WINSTON50 promo code shown at half price; Enterprise by contact | No public plans: institutional licence through Turnitin Originality; price by sales |
| 8. API | Yes, docs.gowinston.ai | None published |
| 9. Integrations | Chrome Extension, Google Classroom, WordPress, Zapier, API, GPT apps in ChatGPT | LMS (Moodle, Blackboard, Canvas and others) through the Similarity Report, with no AI indicator embedded in the LMS interface; Microsoft Teams through Feedback Studio only |
| 10. Vendor accuracy and false positive claims | "Winston ranks first on RAID", "100% accuracy on the Chicago Booth benchmark", "zero false positives across 27,743 human documents"; "99.89% of AI text detected at a 1% false-positive rate"; home page headline "the only AI detector with a 99,87% accuracy rate" | No overall accuracy figure; document false positive rate "under 1% for documents with over 20% of AI writing", validated on over 700,000 pre-ChatGPT academic papers before each release; ELL writers 0.014 and native English writers 0.013 false positive rate in the vendor's own research |
| 11. Independent studies | 2 records: Weber-Wulff 2023, RAID 2024 | 4 independent records (Weber-Wulff 2023, Walters 2023, Perkins 2024, Van Vlasselaer 2026) plus the vendor statements record |
| 12. Data retention and privacy statement | Privacy policy (17 July 2026): submitted text and images are collected and stored; deleting a report deletes its content from active storage; deleting the account deletes all submitted content; no training on individually identifiable submissions without consent | No separate repository for AI writing detection; customers choose whether student papers enter the repository; AI results retained as part of the similarity report; full deletion of submissions on request, no partial deletion of the AI component |
| 13. Launch year and ownership | Not stated; Winston AI inc., no parent company stated | 2023; Turnitin, LLC, no parent company stated on the pages read |
| 14. Rankings the card appears in | Independently tested, false positive rate, languages, input limits, false negative rate, claim vs evidence gap, platform integrations, file types | Independently tested, false positive rate, free tiers, languages, input limits, adversarial robustness, false negative rate, platform integrations, file types |
Which studies tested both Winston AI and Turnitin?
One record tested both on the same documents. Weber-Wulff 2023 ran 14 tools on 54 documents in March and April 2023: 18 human-written (9 of them machine-translated), 18 unedited ChatGPT texts and 18 AI texts that had been manually edited or paraphrased with QuillBot. Turnitin was tested two weeks after the other tools, on 14 to 20 April 2023, and the authors note that Turnitin knew the documents were a test suite (arXiv 2306.15666, Section 3, read 8 November 2026). The remaining records test one tool each: RAID 2024 for Winston AI; Walters 2023, Perkins 2024 and Van Vlasselaer 2026 for Turnitin, with the vendor's own statements collected in the Turnitin claims record.
| Source | Winston AI | Turnitin |
|---|---|---|
| Weber-Wulff 2023, 54 documents, binary accuracy (Table 7) | 36 of 54 correct (67%, rank 5 of 14) | 41 of 54 correct (76%, rank 1 of 14) |
| Weber-Wulff 2023, logarithmic accuracy | 75% (rank 4) | 81% (rank 1) |
| Weber-Wulff 2023, false accusations in 18 human documents (Table 9) | 0 | 0 |
| Weber-Wulff 2023, AI documents undetected of 36 (Table 10) | 12 (33.3%), mostly manually edited or QuillBot-paraphrased texts | 10 (27.8%), all among the manually edited and QuillBot-paraphrased texts; the only tool to classify every unmodified ChatGPT document correctly |
| RAID 2024, shared benchmark | False positive rate 0.75%, 0.55%, 0.38% and 0.21% at thresholds 0.25, 0.5, 0.75 and 0.95 (Table 4); accuracy at a fixed 5% FPR 97.2% on open-source chat models, 68.2% on non-chat greedy, 29.5% on non-chat with sampling (Table 5) | Not tested |
| Walters 2023, 126 documents | Not tested | 100% of 126 documents correct, 0 false positives in 42 human papers; the author notes the papers could have been used to train the detector |
| Perkins 2024, 114 samples | Not tested | Baseline mean accuracy 61% (rank 2 of 7); 50% on unmodified AI text falling to 7.9% after adversarial techniques; 0 false accusations in 10 human samples; 88 of 104 AI samples undetected |
| Van Vlasselaer 2026, 160 papers | Not tested | All 40 fully AI papers from ChatGPT Deep Research scored under 20%; 60.0% on 40 hybrid and 50.0% on 40 humanised papers; all 40 human papers correct |
| Turnitin claims record, vendor statements 2023 to 2026 | Document false positive rate under 1% for documents with over 20% AI writing on 800,000 (2023) and over 700,000 (current FAQ) pre-ChatGPT papers; sentence-level false positive rate about 4% (2023); no true positive rate or third-party audit published |
Results as each study reports them: arXiv 2306.15666, arXiv 2405.07940, De Gruyter 10.1515/opis-2022-0158, DOI 10.1186/s41239-024-00487-w, DOI 10.1007/s40979-026-00226-w, read 8 and 9 November 2026. "Not tested" means the paper did not run that tool.
What do the two cost over 12 months?
| Plan | Monthly as stated | Annual as stated | Inclusions as stated | Checked on |
|---|---|---|---|---|
| Winston AI Free | $0 /month | 2,000 credits for a 14-day trial, not recurring | 8 November 2026 | |
| Winston AI Essential | $18 /month (shown struck through beside $9 with promo code WINSTON50) | $10.00 /month billed annually, $60.00/year (shown beside $5.00 with the code) | 100,000 credits a month; AI, image and deepfake detection, plagiarism detection, writing feedback, OCR, PDF reports | 8 November 2026 |
| Winston AI Advanced | $29 /month ($14.50 with the code) | $16.00 /month billed annually, $96.00/year ($8.00 with the code) | 200,000 credits a month; up to 5 team members | 8 November 2026 |
| Winston AI Elite | $49 /month ($24.50 with the code) | $26.00 /month billed annually, $156.00/year ($13.00 with the code) | 500,000 credits a month; unlimited team members | 8 November 2026 |
| Winston AI Enterprise | Contact sales | 8 November 2026 | ||
| Turnitin AI writing detection | No public price | No public price | Licensed with Turnitin Originality, or as the AI writing add-on for iThenticate 2.0; Similarity, Feedback Studio and Originality Check customers are told to speak to their account manager | 8 November 2026 |
Prices in USD as shown with the $ symbol on gowinston.ai/pricing, checked 8 November 2026; the page states no currency. The annual toggle reads "Save 45%". Turnitin publishes no price for AI writing detection on any page read (guides.turnitin.com, read 8 November 2026).
One of the comparisons in the compare hub. The cards are Winston AI and Turnitin, and the home board answers which AI detectors exist and who has tested them?
Which card fits which reader?
- Choose Winston AI ifyou are an individual, a team or a developer: plans start at $18 a month with a 14-day trial, and the API is documented at docs.gowinston.ai (gowinston.ai/pricing, read 8 November 2026). Turnitin sells to institutions only.
- Choose Turnitin ifyour institution already licenses Turnitin Originality and submissions arrive through Canvas, Moodle or Blackboard: the AI indicator appears inside the Similarity Report, with no separate workflow (guides.turnitin.com, read 8 November 2026).
- Choose Winston AI ifyou check images or scanned handwriting: the card states image detection and OCR, while Turnitin's AI writing detection scores typed prose only (gowinston.ai/pricing, read 8 November 2026).
- Choose Turnitin ifyou want the tool that ranked first of 14 in Weber-Wulff 2023: 41 of 54 documents correct and every unmodified ChatGPT document caught, against Winston AI's 36 of 54 (arXiv 2306.15666, Table 7).
- Choose Winston AI ifyour texts are in Polish, Italian, Indonesian, Romanian or Chinese: those five are on Winston AI's list of 11 and not on Turnitin's list of 7 (gowinston.ai/ai-content-detector, guides.turnitin.com, read 8 November 2026).
- Choose Turnitin ifyou check documents of 300 to 30,000 words and want a stated miss profile on edited AI text: in Perkins 2024 its detection fell from 50% to 7.9% after adversarial edits, a figure Winston AI has no equivalent of in the index (DOI 10.1186/s41239-024-00487-w, Table 8).
How does the evidence compare, tool by tool?
Winston AI
- Register ID
- AIDI-D-0005
- Study records
- 2 in the index: Weber-Wulff 2023, RAID 2024
- Shared with Turnitin
- 1: Weber-Wulff 2023
- Vendor accuracy claim
- Winston ranks first on RAID, achieved 100% accuracy on the Chicago Booth benchmark, and recorded zero false positives across 27,743 human documents in published evaluations. 99.89% of AI text detected at a 1% false-positive rate, including adversarial attacks. (Headline elsewhere on the home page: The only AI detector with a 99,87% accuracy rate.)
- Free tier
- Free: $0 /month, 2,000 credits / 14 day trial (not recurring). API: register for free and receive 2,500 credits.
- Languages
- 11 stated
Turnitin
- Register ID
- AIDI-D-0002
- Study records
- 5 in the index: Weber-Wulff 2023, Walters 2023, Perkins 2024, Van Vlasselaer 2026, Turnitin claims
- Shared with Winston AI
- 1: Weber-Wulff 2023
- Vendor accuracy claim
- None published
- Free tier
- None. AI writing detection is only available to customers that license Turnitin Originality (or the AI writing add-on for iThenticate 2.0).
- Languages
- 7 stated
How this comparison is built
- Cards compared
- Winston AI and Turnitin
- Fields
- The 14 fields of every card, in card order
- Shared study records
- 1: Weber-Wulff 2023
- Fields checked
- 8 November 2026
- Records in the studies index
- 35 records
Both columns are drawn from the same 14 fields in the index data file, read on 8 November 2026 from the vendor page recorded on each card, and from the studies index, where each result is copied as the paper reports the figure, with the base stated. Weber-Wulff 2023 is the one record that ran both tools on the same documents, so its rows sit first in the evidence table; the single-tool records follow with "Not tested" in the other column. A vendor's accuracy or false positive statement is quoted and attributed and never placed in the same cell as a study figure. The rules, the recheck schedule (next pass 8 December 2026) and the correction route are on the methodology page; the independently tested ranking sorts every card on the study count used in the first sentence.
Where each figure comes from
Values as each vendor states them on gowinston.ai, gowinston.ai/ai-content-detector, gowinston.ai/pricing, gowinston.ai/privacy-policy, the Turnitin AI writing detection FAQs and turnitin.com/solutions/topics/ai-writing, all read 8 November 2026. An empty cell means the card has no published value for the field.
Questions about Winston AI and Turnitin
Which study tested both Winston AI and Turnitin?
Weber-Wulff 2023, on 54 documents: Turnitin 41 of 54 correct (rank 1 of 14) and Winston AI 36 of 54 (rank 5), with 0 false accusations in 18 human documents for both (arXiv 2306.15666, Tables 7 and 9, read 8 November 2026).
Which has the lower false positive rate?
Both recorded 0 of 18 in Weber-Wulff 2023. Turnitin also recorded 0 of 42 in Walters 2023, 0 of 10 in Perkins 2024 and 0 of 40 in Van Vlasselaer 2026; Winston AI recorded 0.55% at threshold 0.5 in RAID 2024 (arXiv 2405.07940, Table 4). The bases differ, so the rates are not like for like.
Which missed more AI text?
In the shared study Winston AI missed 12 of 36 AI documents and Turnitin 10 of 36, both mostly on edited or paraphrased texts (arXiv 2306.15666, Table 10). Perkins 2024 later recorded 88 of 104 AI samples undetected for Turnitin after adversarial techniques; Winston AI was not in that study.
Can an individual buy Turnitin's AI detection?
No. The FAQ states it is available only to customers that license Turnitin Originality, or as an add-on to iThenticate 2.0 (guides.turnitin.com, read 8 November 2026). Winston AI sells monthly plans from $18 to individuals.
Which supports more languages?
Winston AI names 11 languages and Turnitin 7, as read on 8 November 2026 (gowinston.ai/ai-content-detector, guides.turnitin.com). Turnitin's paraphrase and bypasser detection is English only.
Does either have an API?
Winston AI documents one at docs.gowinston.ai and gives 2,500 credits on registration; Turnitin publishes no API for AI writing detection on the pages read (gowinston.ai/ai-content-detection-api, read 8 November 2026).
What is the minimum text each will score?
Turnitin does not process documents with fewer than 300 words of prose in evaluated sentences; Winston AI states a 200,000-character maximum and no minimum on the pricing page (guides.turnitin.com, gowinston.ai/pricing, read 8 November 2026).
Sources and revisions
Sources
- Winston AIgowinston.ai
- Winston AI detector pagegowinston.ai/ai-content-detector
- Winston AI pricinggowinston.ai/pricing
- Winston AI APIgowinston.ai/ai-content-detection-api
- Winston AI privacy policygowinston.ai/privacy-policy
- Turnitin AI writing detection FAQsguides.turnitin.com/hc/en-us/articles/284...
- Turnitin AI writing pageturnitin.com/solutions/topics/ai-writing
- Weber-Wulff et al. 2023arxiv.org/pdf/2306.15666
- Dugan et al. 2024 (RAID)arxiv.org/pdf/2405.07940
- Walters 2023degruyterbrill.com/document/doi/10.1515/o...
- Perkins et al. 2024doi.org/10.1186/s41239-024-00487-w
- Van Vlasselaer 2026 (read 9 November 2026)doi.org/10.1007/s40979-026-00226-w
