How we chose and compared the tools
Textumi is our product, and we wrote this page. Read it with that in mind: we have tried to describe every tool, ours included, by what it states about itself and nothing more.
We chose detectors that people who search in English are likely to meet: widely used international tools and writing services that include a detector. They appear in alphabetical order. The order is not a ranking.
Every fact on this page comes from the tools' websites, help pages or documentation, last checked on 19.10.2026. If we couldn't open a tool's pages or they contradicted each other, we mention this. We don't include prices as they change frequently: look at the pricing pages of the individual tools as well as our Textumi pricing page.
We did not run an accuracy test for this page, and we do not repeat accuracy figures that companies publish about their own detectors. Each company tests on its own texts, so those numbers cannot be compared with each other.
The detectors at a glance
Checked on 19.10.2026. The table shows what each tool states on its own pages. “See its site” means we could not confirm the point there.
| Tool | Detection languages | Without an account | Also offers | Extensions, apps, connectors |
|---|---|---|---|---|
| Copyleaks | 30 languages in its documentation | See its site | Plagiarism check, API | MCP server |
| GPTZero | English and 20+ other languages | Up to 10,000 characters per scan | Plagiarism check, Writing Replay, API | Chrome extension, Google Docs and Word add-ons |
| Originality.ai | 31 languages including English | 3 scans a day, up to 2,000 words each | Plagiarism check, API | Chrome extension, Moodle plugin, MCP connector |
| QuillBot | English, French, Spanish, German, Dutch, Portuguese, according to its blog | Under 1,200 words | Paraphraser, humanizer, plagiarism check | Extensions for Chrome, Edge, Safari and Word, macOS app |
| Textumi | 20 languages | 5 to 250 words, 3 checks a day | Humanizer with fact checks | Chrome extension, macOS app for Apple silicon, MCP connector |
| Winston AI | Lists differ between its pages | No, an account with a trial | Plagiarism check, AI image detection, API | Chrome extension, MCP server |
| ZeroGPT | “All languages”, no list published | See its site | Humanizer, paraphraser, plagiarism check and other tools, API | WhatsApp and Telegram access |
What each detector offers
Copyleaks
AI detection and plagiarism checking are available on the Copyleaks website and via an API. It supports 30 languages for AI detection, including German, French, Spanish, Polish and Ukrainian. It accepts documents of up to 2,000 pages, and the docs describe an MCP server for Claude and other AI tools. The main website would not open, so these details were confirmed in the documentation only.
It suits teams and developers who need AI and plagiarism checks in many languages, built into their own systems.
GPTZero
GPTZero was founded in January 2023. GPTZero has a help page that mentions English and over 20 other languages. It scans up to 10,000 characters without an account, and with an account it takes longer texts and batches of files. GPTZero has a plagiarism checker, a Chrome extension, add-ons for Google Docs and Microsoft Word, integrations for Canvas and Google Classroom, and Writing Replay, which shows how a document was typed.
It suits teachers and students who want checks inside Docs, Word, Chrome or their school's learning platform. Our side-by-side page compares it with Textumi in detail.
Originality.ai
According to Originality.ai, there are 31 languages available for AI detection, including English. Users can perform up to three AI detection scans per day for up to 2,000 words each (without having to sign up). It also includes a plagiarism checker, a Chrome extension that works with Google Docs, a Moodle plugin, an API, and an MCP connector for ChatGPT and Claude (which its FAQ ties to the Pro and Enterprise plans).
It suits people who want AI and plagiarism checks together, in the browser, in Google Docs or from an AI assistant.
QuillBot
QuillBot has an AI detector tool available in addition to its paraphraser, AI humanizer, grammar checker, and plagiarism checker. It says on its blog that the AI detector checks texts under 1,200 words without signing in and works in English, French, Spanish, German, Dutch and Portuguese. QuillBot lists extensions for Chrome, Edge, Safari, and Word and an app for macOS. We couldn't access its main website, so the information we have comes from its blog.
It suits people who already write with QuillBot's tools and want a quick check in the same place.
Textumi
Textumi is our product. Its AI detector was built and tuned in-house and works in 20 languages, with English and Ukrainian the longest-established. It shows one of five labels, from “Human-written” to “AI-generated”, and with an account the passages behind the result. Without an account it checks 5 to 250 words, three times a day; with an account, up to 12,000 characters per check.
The Humanizer in the same account edits a draft, and compares names, facts, numbers, and logic to the original content before you see it. Textumi runs in the browser, as a Chrome extension, as a macOS application for Macs with Apple silicon and through a connector with your own AI assistant. It has no plagiarism check and no add-ons for Docs or Word.
It suits people who want a detector and a careful Humanizer in one account, on the web, on a Mac or inside their AI assistant.
Winston AI
Winston AI is a text scanning tool that identifies AI-written text and AI-generated images. It also detects plagiarism. One scan takes up to 200,000 characters. The different pages list languages differently, and the pricing page lists English, Spanish, Chinese, German, Polish, Portuguese, Italian, Ukrainian and Dutch languages. It requires an account and starts with a 14-day trial. It offers a Chrome extension and an MCP server that supports tools like Claude, ChatGPT and more.
It suits people who also need image and plagiarism checks, or who work with long documents.
ZeroGPT
ZeroGPT has an AI detector, as well as other features including a humanizer, a paraphraser, a summarizer, a grammar checker, a translator, and a plagiarism checker. Its website says that it can detect in all languages (but does not have a list of these) and its text box allows for up to 15,000 characters of input. There is an API available and you can also use it through WhatsApp and Telegram.
It suits people who want many quick text tools in one place.
How to test a detector yourself
Published accuracy figures come from each company's own tests. A short test on your own texts tells you more about how a tool behaves on the writing you actually check.
- Collect five to ten texts whose origin you know: writing of your own from before AI tools were common, and AI drafts you made yourself in the same language and genre.
- Run every text through each detector you are considering, using the same full text each time rather than single sentences.
- Look first at your human texts. A detector that often flags your own writing will cause trouble, however well it catches AI drafts.
- Try a short text and a long one, and a lightly edited AI draft, because short and edited texts are where detectors disagree most.
- Repeat the test after a few months. Detectors and AI models both change, and an old result may no longer hold.
How to read any detector's result
Every detector, ours included, judges the wording of a text, not how it was written. A label or a percentage is a model's estimate. It is not proof of who wrote the text, and a percentage is not the share of the text that was generated.
Two detectors can judge the same text differently, because they were trained on different examples and draw their thresholds in different places. Short, formal, translated and heavily edited texts give the least stable results everywhere.
Never decide about a person's work from a detector score alone. Look at drafts, notes and version history, and talk to the writer.
Sources and trademarks
Fontes
- Copyleaks documentation, docs.copyleaks.com: supported languages for AI detection, technical specifications, MCP overview. Checked on 19.10.2026.
- GPTZero home page, FAQ and help page “What languages does GPTZero support?”, gptzero.me and support.gptzero.me. Checked on 19.10.2026.
- Originality.ai AI checker page, help page on multi-language detection and MCP page, originality.ai. Checked on 19.10.2026.
- QuillBot blog article about its AI detector, quillbot.com/blog. Checked on 19.10.2026.
- Winston AI home page, pricing page and MCP server documentation, gowinston.ai and docs.gowinston.ai. Checked on 19.10.2026.
- ZeroGPT home page, FAQ and pricing page, zerogpt.com. Checked on 19.10.2026.
All product names are trademarks of their owners. Textumi is not affiliated with or endorsed by any of the companies listed. Textumi wrote this comparison from public information.
Perguntas frequentes
Which AI detector should I use?
Instead of starting with a ranking, start from your own situation: what languages do you need? How long are your texts? Do you also need a plagiarism check? Where do you write? In your browser, in Word or Docs, on a Mac or in an AI assistant? After that, test two or three tools on texts whose origin you know.
Are AI detectors accurate?
No detector is without errors. Every one sometimes flags human writing and misses AI writing, most often in short, formal, translated or edited texts. OpenAI withdrew its own AI text classifier in 2023, citing low accuracy. Treat any result as a signal to look closer, not as a verdict.
Can I check a text without creating an account?
Yes, with several of these tools. Textumi will check 5 to 250 words without an account, three times a day. GPTZero can check up to 10,000 characters, Originality.ai allows three scans a day of up to 2,000 words, and QuillBot's blog names texts under 1,200 words. Limits change, so be sure to check each site.
Is an AI detector the same as a plagiarism checker?
No. A plagiarism checker looks for passages copied from existing sources. An AI detector estimates whether the wording resembles AI writing. Several tools on this page offer both, Textumi offers only AI detection, and a text can be original and still read as AI-written, or the other way round.
Written by ChatGPT? Can a detector tell?
A detector reads the wording of the finished text, not its history, so it cannot confirm that a particular model wrote it. Textumi's detector never names a model, and we have not tested it separately on ChatGPT. Any detector's answer is an estimate from style and is not proof.
Why is Textumi on this list if Textumi wrote it?
Because it is a detector people can choose, and leaving it out would hide our interest rather than remove it. We say plainly that it is our product, list all the tools alphabetically, describe each one from its own pages and point out what Textumi does not offer, such as a plagiarism check or add-ons for Docs and Word.