Vendor compilation: what Originality.ai's accuracy page and 17-study meta-analysis publish about its own detector
- Authors
- Gillham (Originality.ai)
- Venue
- Originality.ai blog: accuracy page (dated 7 November 2026, first published 11 May 2023), meta-analysis post (dated 7 November 2026, first published 12 June 2024), RAID post (dated 28 October 2025, first published 21 May 2024); no DOI
- Published
Originality.ai's accuracy page, by founder Jonathan Gillham and dated 7 November 2026, states that Originality.ai 5.0 and 5.0 Max have "99%+" (accuracy), and the vendor's meta-analysis post of the same date lists 17 third-party studies plus two humanizer benchmarks with a headline figure for Originality.ai of between 83% and 100% in each, under the claim that the tool "has consistently emerged as the most accurate" (Originality.ai accuracy page; meta-analysis post, both read 10 November 2026). Every figure on this page is a figure the vendor published or restated; the index checked two of the 17 studies against its own records of the primary papers and reads the rest as vendor summaries.
The record joins the studies index beside the GPTZero and Pangram vendor benchmarks and the Turnitin claims record as a vendor-statement record: it documents what one company publishes about itself, dated and versioned, so the claim vs evidence gap ranking can set each claim against the studies that tested the same tool. Vendor figures are never averaged with study figures in this index.
One product, scored by its vendor and, in the vendor's restatement, by 17 outside papers. The meta-analysis post names the detectors each study compared, and the index matches those with cards here (meta-analysis post, Rankings table, read 10 November 2026).
What was tested
Detectors tested
| Detector | Version or date stated | Index card |
|---|---|---|
| Originality.ai | 5.0 and 5.0 Max (October 2026) on the accuracy page; 2.0 Standard in the RAID post; detection model 1.4 in Walters 2023; unversioned in most listed studies | Originality.ai |
| GPTZero | named as a competitor in 11 of the 17 listed studies, no version | GPTZero |
| Copyleaks | named in 7 listed studies, no version | Copyleaks |
| ZeroGPT | named in 7 listed studies, no version | ZeroGPT |
| Turnitin | named in 5 listed studies, no version | Turnitin |
| Winston AI, Sapling, GPT-2 Output Detector | named in 3 listed studies each, no version | Winston AI, Sapling, GPT-2 Output Detector |
| Writer, Detecting-AI, DetectGPT | named in 2 listed studies each | Writer, Detecting-AI, DetectGPT |
| Binoculars, Fast-DetectGPT, QuillBot, Grammarly, Isgen, Smodin, ContentDetector.AI, Content at Scale | named in 1 listed study each | Binoculars, Fast-DetectGPT, QuillBot, Grammarly, Isgen, Smodin, ContentDetector.AI, BrandWell |
| Crossplag, Aidetector, XLM-RoBERTa | named in 1 listed study each | no card |
| Pangram | named only in the humanizer-benchmark row | Pangram |
Sample
Names as the vendor prints them in the "Key Competitors" column; the vendor restates no competitor's figure in that table (meta-analysis post, read 10 November 2026).
The accuracy page's own figures come from the vendor's model release history, which gives one or two numbers per release with no test-set size: 1.4 (April 2023) a false positive rate of 1.5%; 3.0 Turbo (February 2024) accuracy "from 90.2% to 98.8%" on "our toughest testing dataset"; 1.0.0 Lite (July 2024) 98% (accuracy) "under 1% false positive rate"; Multilingual 2.0.0 (May 2025) 97.8% (accuracy), false negatives 1.99%, false positives 2.4%; 1.0.2 Lite and 3.0.2 Turbo (September 2025) false positive rates of 0.5% and 1.5%; and 5.0 and 5.0 Max (October 2026) 99%+ (accuracy), with the classic models retired in September and October 2026 (Originality.ai accuracy page, Model Release History, read 10 November 2026).
The vendor sizes three of the sets it restates, RAID at 6,287,820 texts across 12 detectors, 11 generators, 8 domains and 11 attacks at a 5% false positive threshold, Walters 2023 at 126 papers and 16 detectors, and the "Empirical Study" at 11,580 samples and 6 tools, and sizes none of its own release tests (RAID post; meta-analysis post, Studies 1 and 2, read 10 November 2026). The index has read RAID and Walters 2023 in the primary source and the other 15 only here.
What the study reports
| Metric | Value | Base |
|---|---|---|
| Originality.ai 5.0 and 5.0 Max (accuracy page) | 99%+ (accuracy) each | not stated |
| Model history false positive rates (accuracy page) | 1.4 1.5%; Turbo 3.0 2.8%; Lite 1.0.0 under 1%; Multilingual 2.0.0 2.4%; Lite 1.0.2 0.5%; Turbo 3.0.2 1.5% | not stated |
| RAID, vendor restatement (RAID post) | 85% (accuracy) on the base set "vs the closest competitor at only 80%"; 98.2% on ChatGPT text; 96.7% on paraphrased text "compared to the next closest competitor at 80%"; 1st in 9 of 11 attacks, 1st in 5 of 8 domains; "performed poorly" on homoglyph and zero-width space attacks; model 2.0 Standard | 6,287,820 texts at a 5% false positive threshold, as the vendor states |
| Walters 2023, vendor restatement (meta-analysis, Study 2) | 97% overall; 100% on GPT-3.5 and GPT-4 papers; 95% on human papers | 126 documents |
| "Empirical Study", vendor restatement (Study 1) | 97% (accuracy), 98% precision, 96% recall; 5,547 true positives, 243 false negatives, 94 false positives | 11,580 samples |
| Other listed studies, vendor headline per row (Rankings table) | 100% (medical writing); 96% (oncology abstracts); 91% (college coursework); 96.6% (academic writing); 97.6% AUC (biomedical publishing); 98 to 100% (systematic review); 98% (STEM writing); 100% or near (Arabic); 98.61% Lite (scholarly fairness); 100% (multi-authored Spanish); 96% (polished Arabic); 83% sensitivity (academic contexts); 100% (obfuscation); 98% (dentistry); 92.8% (federated learning) | per-study bases not restated in the table |
| Humanizer benchmarks, vendor restatement (Rankings table) | 89.8% in HumanizerBench, 96.0% in HumanizerEval, Originality.ai 5.0 | not restated |
Every figure is a vendor figure, printed on the page named in its row (Originality.ai accuracy page; meta-analysis post; RAID post, read 10 November 2026).
All values as printed by the vendor on 10 November 2026; the accuracy page repeats the same table.
Two of the 17 studies are in this index. For RAID, the vendor's 85% base accuracy, 96.7% under paraphrase and the two weak attacks match what the RAID record prints from the paper: 85.0 with no attack, 96.7 under paraphrase and 9.3 under homoglyphs at a 5% false positive threshold, with a 0.25% false positive rate at threshold 0.5 that the vendor's post does not quote (RAID post, Findings 1 to 4, read 10 November 2026). For Walters 2023, the vendor restates 97% overall where the Walters record prints 98% correct, 0% incorrect and 2% uncertain on 126 documents from the paper's own table; the per-class figures of 100%, 100% and 95% agree (meta-analysis post, Study 2, read 10 November 2026).
What the compilation leaves out is as dated as what it includes. Five records in this index scored Originality.ai and are absent from the vendor's list: Orenstrakh 2023 with 7 false positives in 114 human coursework texts, Pegoraro 2023 with a 7.6% true positive rate on ChatGPT answers, Liang 2023 with an average 61.22% false positive rate across seven detectors on TOEFL essays, Jabarian and Imas 2025 with a false positive rate of 0.0011 at threshold 0.5, and Epoch AI 2026 with 19 of 495 pre-2022 human passages flagged by Turbo 3.0.2 (meta-analysis post, Rankings table, read 10 November 2026). The vendor's own RAID post also records that "a sub 1% false positive solution is needed", which the Lite model later claimed at 0.5% (RAID post, read 10 November 2026).
Limits the authors state
The vendor states that "no AI detection tool is ever going to be 100% perfect", that "a single number related to a detector's effectiveness without additional context is useless", and that "many of the tests in this meta-analysis were conducted on legacy models", pointing readers to the 5.0 launch post (Originality.ai accuracy page; meta-analysis post, read 10 November 2026). The RAID post notes the study "did not include the domain/type of content we at Originality.ai focus most on, i.e. web content".
Evident from the pages: the vendor selected which studies to list and which figure to headline from each; the release-history figures name no test-set size; the meta-analysis "Key Findings" line counts "all 6 published 3rd party studies" while the table lists 17; the Walters figure differs from the paper by one point; and the accuracy page is the source of the claim the Originality.ai card quotes.
Which cards this study feeds
- AIDI-R-02AI detector false positive rates, ranked
- AIDI-R-09AI detector false negative rates, ranked
- AIDI-R-10AI detector accuracy claims vs published results, ranked by the gap
One card takes a dated vendor-compilation line, and no competitor card takes a figure, because the vendor restates none (Originality.ai accuracy page; meta-analysis post, read 10 November 2026).
None of these figures enters the false positive rate ranking or the false negative rate ranking, which take study results only; the claim vs evidence gap ranking is where the "99%+" claim meets Walters 2023, RAID and Epoch AI 2026. How this record is sourced explains the rule, and the home page shows which AI detectors exist and who has tested them.
Related records: the GPTZero and Pangram vendor benchmarks record scores Originality lite-102 at a 1.88% false positive rate on a competitor's set; Epoch AI 2026 and RAID 2024 are the outside tests the vendor's claim can be set against.
Questions about this study
What accuracy does Originality.ai claim for its current detector?
"99%+" (accuracy) for both Originality.ai 5.0 and 5.0 Max, launched October 2026, with no test-set size on the accuracy page dated 7 November 2026; the most recent false positive rates in the same release history are 0.5% for Lite 1.0.2 and 1.5% for Turbo 3.0.2, models retired in September 2026 (Originality.ai accuracy page).
Does the vendor's meta-analysis match the primary papers?
For the two studies this index has read, mostly: the RAID figures of 85% base and 96.7% under paraphrase match the paper, while the Walters 2023 figure of 97% overall is one point below the paper's 98% correct on 126 documents (meta-analysis post, Studies 2 and 3; RAID post).
Which studies does the Originality.ai compilation leave out?
Five tests of the product recorded in this index: Orenstrakh 2023 (7 false positives in 114), Pegoraro 2023 (7.6% true positive rate), Liang 2023 (61.22% average false positive rate across seven detectors), Jabarian and Imas 2025 (0.0011 false positive rate) and Epoch AI 2026 (19 of 495 human passages flagged) (meta-analysis post, Rankings table).
Is the Originality.ai meta-analysis a study?
No: it is a vendor-written compilation of other people's studies, one headline figure per paper and no competitor figure, and this index records it as a vendor statement never averaged with study results (meta-analysis post).
Source and revisions
Source
Gillham, J. (2026-11-07; first published 2023-05-11). Why AI Detection Matters and How to Measure It. Originality.ai, https://originality.ai/blog/ai-accuracy, read 10 November 2026. Gillham, J. (2026-11-07; first published 2024-06-12). AI Detection Accuracy Studies: Meta-Analysis of 17 Studies. Originality.ai, https://originality.ai/blog/ai-detection-studies-round-up, read 10 November 2026. Gillham, J. (2025-10-28; first published 2024-05-21). Originality.ai is the Most Accurate AI Detector According to an Extensive Study "RAID". Originality.ai, https://originality.ai/blog/robust-ai-detection-study-raid, read 10 November 2026. Visible dates are the page bylines; first-published dates are the pages' datePublished metadata. No DOI.



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