Textumi vs Grammarly: how the two AI detectors differ

Textumi and Grammarly at a glance

Checked on 20.10.2026. Grammarly facts come from Grammarly's own website, help centre, developer portal and blog; Textumi facts come from our product. Features change, so check both sites before you decide.

How each tool shows a result

Textumi places a needle on a scale from “Human” to “AI”. It also picks one of five labels (from “Human-written” to “AI-generated”). With an account, you can also see which passages weighed most in the result. For text below 50 words, you'll see “Too little text to judge” instead of a label.

Grammarly's free detector shows the percentage of a text that appears to be AI-generated and scores the text section by section. Its help centre says the percentage should not be used as an objective source of truth, and in its paid products flagged parts are underlined.

Grammarly also provides Authorship, which is a different kind of evidence. It doesn't evaluate the finished text, but instead records how a document was written, which parts were typed, pasted or AI assisted, then allows you to share a replay and a report. The website for Authorship states that it is available in Grammarly Free and Grammarly Pro.

Which languages each detector covers

Textumi can detect AI writing in 20 languages of text. The longest record belongs to the English and Ukrainian detectors, and the detectors for the other languages were constructed and tested using a smaller set of texts. Some of the text detectors also fail to detect many AI texts of other genres, so a longer text delivers a more reliable result in those languages.

Grammarly's blog says its AI detection is available for English content only. Grammarly has detector pages in German, French and Spanish, but they do not name other detection languages.

Rewriting a draft: two different approaches

Textumi's Humanizer is used in the same account as the detector. It will rewrite the draft so that it sounds more natural. The rewritten text will then be checked against your original text: facts, names, numbers, exact names like quoted labels, and each sentence's logic. Any version that doesn't pass the test will not be shown and your original will be beside the result.

The Humanizer takes 50 to 2,000 words in English and up to 1,000 words in the other languages. It does not promise a lower score in any detector.

Grammarly offers an AI humanizer and a paraphrasing tool. Its humanizer page says the tool is not intended to bypass AI detectors, and its help centre notes that text rewritten by Grammarly's own agents will likely be flagged by its detector.

Where you can use each tool

Textumi is available in four places, and all can be accessed with one account. The web workspace is for pasted text, files, and public web pages. Textumi for Chrome checks and rewrites text on any web page from a side panel. Textumi for macOS puts the AI Detector and Humanizer on a toolbar above your other apps, and it will only work on Macs with Apple silicon. The MCP connector allows Claude, ChatGPT, and other assistants to check and rewrite text with Textumi right within the conversation.

Textumi for Chrome

Grammarly works where you already write: desktop apps, including one for Mac, browser extensions, Microsoft Office, Google Docs and phone apps. Its help centre describes AI detection in Google Docs and Word as a paid feature, and Grammarly for Education adds Authorship in learning platforms such as Canvas.

Textumi has no add-ons for Docs or Word. If you write in Word or Docs, you can import the file into the workspace or select the text in the macOS app.

Privacy and history

Textumi stores submitted texts and results encrypted, and detection runs on Textumi's own servers. For rewriting, the text also goes to the external AI model provider named in our privacy policy. On Individual and Professional, your private History keeps requests for 30 days, and you can delete them earlier. A check without an account keeps no text.

Grammarly's trust page says it does not sell or monetize user content and that users can opt out of product improvement and training. For its full rules, read Grammarly's privacy policy and trust pages.

Who each tool suits

Grammarly suits you if you want writing help and AI detection inside the apps you already use, if you or your school want Authorship to show how a document was written, or if you need a plagiarism check next to grammar and style suggestions in English.

Textumi suits you if you check texts in languages other than English, if you want the detector and a Humanizer with fact checks in one account, or if you want checks and rewrites from inside your AI assistant. It also suits you if you prefer a plain label with the passages behind it to a percentage.

See Textumi plans

Sources and trademarks

Grammarly, Superhuman and GPTZero are trademarks of their owners. Textumi is not affiliated with or endorsed by Grammarly or Superhuman. Textumi wrote this comparison about its own product and a competitor from public information.