QuillBot AI detector
Vendor QuillBot Official site quillbot.com/ai-content-detector How this card is sourced
Updated · AI Detector Index editors
AI Detector by Quillbot detects AI text in 6 languages according to the vendor's blog read on 8 November 2026, and runs free scans of up to 1,200 words with no sign-up on the detector page read the same day (quillbot.com). QuillBot is one of two Learneo brands in the index, beside Scribbr, and the detector is bundled into QuillBot Premium rather than sold alone. How this card is sourced explains the rules; the full detector index holds the other twenty-one cards.
What QuillBot detects
| Field | Value | Source |
|---|---|---|
| Content types detected | Text, image | quillbot.com/ai-content-detector |
| Generators covered | GPT-6, GPT-5, ChatGPT, Gemini, Claude, Llama, other LLMs | quillbot.com/ai-content-detector |
| Languages | English, French, Spanish, German, Dutch, Portuguese | quillbot.com/blog/quillbot-tools/ai-detector |
| Input limits | Minimum 80 words per scan. Free: up to 1,200 words per scan. Premium: no word limit for detection scans. Paste text or upload doc (file types and size not published); Premium bulk upload of many documents at once. | quillbot.com/ai-content-detector |
| Free tier | Up to 1,200 words per scan, up to 6 scans per day, 1 free explainer card; no sign-up for scans under 1,200 words | quillbot.com/ai-content-detector |
| Integrations | Google Chrome extension, Microsoft Edge extension, macOS app, Word add-in, Android keyboard and app, iOS keyboard and app | quillbot.com/premium |
| Ownership | Part of the Learneo family of businesses (stated on scribbr.com, a sister Learneo brand; QuillBot's own about page did not load) | scribbr.com/about-us |
| Independent studies | 2 records | Studies index |
QuillBot covers two modalities, text and image. The detector page names GPT-6, GPT-5, ChatGPT, Gemini, Claude, Llama and other LLMs (quillbot.com/ai-content-detector, read 8 November 2026).
The 6 languages are English, French, Spanish, German, Dutch and Portuguese, as enumerated in the vendor's blog (QuillBot blog, read 8 November 2026). The detector page itself says only "Multilingual support" without a list, and an older cached copy of that page said English only; this card uses the blog list because the blog is the only enumerated list on a vendor page.
On edited AI text, QuillBot says results distinguish four categories: Generated by AI, Generated and refined by AI, Written by a human and refined by AI, and Written by a human, and that "Most AI checkers can't differentiate between text that's been entirely generated with AI tools and text that's been refined using AI assistance" (quillbot.com/blog/quillbot-tools/ai-detector/, read 8 November 2026). The vendor makes no claim about detecting humanizer output.
QuillBot is part of the Learneo family of businesses, as stated on the about page of its sister brand Scribbr (scribbr.com, read 8 November 2026). Integrations are Chrome and Microsoft Edge extensions, a macOS app, a Word add-in, and Android and iOS keyboards and apps (quillbot.com/premium, read 8 November 2026).
Limits and plans
| Plan | Price | Limits | Checked on |
|---|---|---|---|
| Premium | $8.33 USD Per month, billed annually | Full access to AI Detector, no word limit for detection scans, unlimited scans, unlimited explainer cards. The detector is bundled; there is no detector-only plan. Monthly price not shown with the annual toggle on. | |
| Team Plan | Price not shown on the premium page (Explore Team Plan). |
Each scan needs a minimum of 80 words. Free scans take up to 1,200 words; Premium removes the word limit for detection scans and adds bulk upload of many documents at once. Input is pasted text or an uploaded document (quillbot.com/ai-content-detector, read 8 November 2026).
The free tier allows up to 1,200 words per scan and up to 6 scans per day, with 1 free explainer card, and scans under 1,200 words need no sign-up (quillbot.com/ai-content-detector, read 8 November 2026). The allowance is stated per day, so the index carries no monthly figure for QuillBot.
Prices below come from the QuillBot Premium page, read 8 November 2026, in USD with the annual toggle on.
What the vendor claims
Detect AI text reliably with a 99% detection rate, according to independent evaluations from RAID.
QuillBot says: "Detect AI text reliably with a 99% detection rate, according to independent evaluations from RAID." The sentence is from the QuillBot AI detector page, read 8 November 2026. The vendor publishes no accuracy split by language or by generator.
On false positives, QuillBot says: "Get AI likelihood estimates you can trust and avoid false positives. When the result is unclear, our model tends to classify texts as human written, which reduces false positives." (quillbot.com/ai-content-detector, read 8 November 2026). QuillBot gives no numeric false positive rate, which is why the card is absent from the false positive rate ranking.
QuillBot also says: "Scores are signals, not verdicts. Never make an academic or employment decision on a detector score alone", and "The longer the text the better the results" (quillbot.com/ai-content-detector, read 8 November 2026). A QuillBot detection rate quoted from RAID describes how the model did on the RAID set, and the four-way category on a result is a model's grouping, not a finding of fact about the writer.
What independent studies found
- AIDI-S-0023Kar 20242024
Read one 500-word ChatGPT 3.5 article as 100% AI and the same text after a QuillBot paraphrase as 90 AI; 100 after Grammarly and ChatGPT paraphrases (Table 1, single text).
- AIDI-S-0024Alshammari and Rao 20252025
Average AI score 98.4% on 49 DeepSeek-V3 answers and average human score 100% on 49 human answers; 95.4% on DeepThink text, falling to 58% after a humanized paraphrase (Tables III and V, March 2025).
No study in the index has tested QuillBot's detector, although Weber-Wulff 2023 used QuillBot's paraphraser to produce test texts for other tools; the detectors with a study record are listed in the independently tested ranking.
Two records joined the list on 9 November 2026, the card's first: Kar 2024 read one 500-word ChatGPT 3.5 article at 100% AI, 90 AI after QuillBot's own paraphrase and 100 after Grammarly and ChatGPT paraphrases, and Alshammari and Rao 2025 recorded a mean AI score of 98.4% on 49 DeepSeek-V3 answers, 95.4% on DeepThink text and 58% after a humanized paraphrase; both print scores rather than rates, so the false positive, false negative and robustness fields stay empty.
Where QuillBot appears in the index
Rankings
- AIDI-R-01AI detectors ranked by independent testing Two records added in the fifth wave on 9 November 2026, Pegoraro 2023 and Fleckenstein 2024, changed nine counts and none: Pegoraro 2023 tested ZeroGPT, GPTZero, Copyleaks, Originality.ai, Writer, Content at Scale (BrandWell), DetectGPT, the GPT-2 Output Detector and GLTR, lifting GPTZero to 12, the GPT-2 Output Detector to 10, Copyleaks to 7 and Originality.ai and ZeroGPT to 6; Fleckenstein 2024 tested 289 teachers and no software, so it counts for no card ([Fleckenstein 2024 record](/studies/fleckenstein-2024-teachers/)). Illuminarty, one of four cards added in the same wave, joined with its one image record from Ha and Passananti 2024, so 18 of 72 cards now qualify.
- AIDI-R-04AI detectors ranked by languages supported
- AIDI-R-07AI image, voice, video and code detectors ranked by independent studies
- AIDI-R-11AI detectors ranked by named integration surfaces
- AIDI-R-13AI detectors ranked by minimum text length per check
- AIDI-R-16AI detectors ranked by the free checks per day the vendor states
- AIDI-R-17AI detectors ranked by the generator models the vendor names
Fits these use cases, questions and comparisons
- AIDI-U-08AI detectors for researchers checking their own manuscripts
- AIDI-U-11AI text detectors for newsrooms and fact desks
- AIDI-Q-01Is there a 100% accurate AI detector? What published tests show
- AIDI-C-07ZeroGPT vs Scribbr vs QuillBot: three free AI detectors on the same 14 fields
- AIDI-C-11Scribbr vs QuillBot AI detector: two Learneo brands on the same 14 fields
- AIDI-C-14QuillBot vs Turnitin AI detector: a free consumer check against an institutional licence, on the same 14 fields
- AIDI-UP-05Studies digest, Q1 2027: the thirteen evaluations added since the Q4 digest, with one headline figure each
QuillBot qualifies for one ranking, the languages ranking, on a count of 6 (detectors.json, read 8 November 2026). With no study record the card is absent from the independently tested ranking, with no numeric false positive figure the card is absent from the false positive rate ranking, and with a per-day rather than per-month allowance the card is absent from the free tiers ranking.
QuillBot fits business through the Team Plan, agencies through Premium bulk upload, and recruiters through the 6 free scans a day on plain text (quillbot.com/ai-content-detector, read 8 November 2026). The nearest cards by product shape are Scribbr, which is part of QuillBot inside the same Learneo group, and Grammarly, another writing-suite detector. The home page carries the index of AI detectors.
ZeroGPT vs Scribbr vs QuillBot, added 9 November 2026, sets this card's free tier, 1,200 words per scan and 6 scans a day, beside the two other free detectors and the one study that tested two of them.
Later on 9 November 2026 the Kar 2024 and Alshammari and Rao 2025 records moved the card into the independently tested ranking with 2 records.
QuillBot vs Turnitin, added 10 November 2026, sets this free consumer check beside the institutional licence a student's instructor runs, with no study that ran both: Turnitin's four measured zeros on human text against this card's two records of displayed scores and its vendor-submitted RAID leaderboard entry.
Questions about QuillBot AI detector
Is the QuillBot AI detector free?
Yes, with limits. Free scans take up to 1,200 words, up to 6 scans per day, with 1 free explainer card and no sign-up under 1,200 words, per the detector page read 8 November 2026. Premium at $8.33 USD per month billed annually removes the word limit.
How many languages does QuillBot detect?
Six: English, French, Spanish, German, Dutch and Portuguese, per the vendor's blog read 8 November 2026. The detector page says only "Multilingual support", so the count of 6 comes from the blog's enumerated list and is the figure that ranks the card.
Has QuillBot's detector been tested in a study?
No study in the index has tested QuillBot's detector as of 8 November 2026. The vendor's own 99% detection rate cites RAID, but the RAID record in this index lists GPTZero, Originality.ai, Winston AI and ZeroGPT and does not include QuillBot.
What does the minimum of 80 words mean?
QuillBot will not score a passage shorter than 80 words, per the detector page read 8 November 2026. The vendor adds that longer text gives better results, so a result on a passage just above the minimum carries less weight than one on a full document.
Sources and revisions
Sources
- quillbot.com/ai-content-detectorRead 8 November 2026
- quillbot.com/premiumRead 8 November 2026
- quillbot.com/blog/quillbot-tools/ai-detectorRead 8 November 2026
- scribbr.com/about-usRead 8 November 2026
Revision log
- Card created2026-11-09: three-way free detector comparison linked (fifth wave)2026-11-09: kar 2024 and alshammari and rao 2025 records added in the sixth wave, 2 study records2026-11-10: quillbot vs turnitin comparison linked (tenth wave)
). Illuminarty, one of four cards added in the same wave, joined with its one image record from Ha and Passananti 2024, so 18 of 72 cards now qualify.: register plate](/img/independently-tested-480.webp)
