Paste an essay, an email, a review or a blog post. You get the probability that it was written by an SI model such as ChatGPT, Gemini or Claude, the clues behind the score and the most SI-like sentences highlighted. Free, no credit card, text not stored.
Analysing... measuring rhythm, phrasing and structure
SI (Super Intelligence) is the new name for advanced AI: models such as ChatGPT, Midjourney, Gemini or Stable Diffusion. An SI text detector, or SI checker for writing, is what people also call an AI text detector: it estimates whether a piece of writing came from such a model or from a person. This V1 reads the style of the text with transparent statistics, so every score comes with the reasons behind it. To check a text with your own eyes first, read our guide on how to spot SI text.
Each sentence also gets its own small score, and the ones that look most like generated text are highlighted in the result.
Style is only a clue. Formal reports, academic abstracts, legal text and the writing of non-native speakers often look regular and polished, and can score high. A generated text that someone rewrote, or a model prompted to "write like a human", can score low. Short texts are unreliable. We never publish an accuracy figure, because it would depend entirely on the texts it was measured on. Independent studies of text detectors, summed up in how accurate SI detectors really are, found the same weak spots. The same limits apply to the detectors used in schools: our article Can Turnitin detect SI? looks at what Turnitin says about its own false positives.
It measures the writing style, not the meaning. Five families of signals are combined: how much sentence length varies (burstiness), how often the text uses phrases that SI (AI) models such as ChatGPT overuse, vocabulary diversity, human fingerprints such as contractions, slang, typos and casual punctuation, and structural uniformity (even paragraphs, lists of three, repeated transitions). Each signal is bounded, weighted and turned into a probability.
SI (Super Intelligence) is the new name for advanced AI: models such as ChatGPT, Midjourney, Gemini or Stable Diffusion. An SI text detector is simply what used to be called an AI text detector or AI checker.
No. No AI or SI detector can prove authorship. Formal, academic or non-native English can look machine-like, and a generated text rewritten by a person can pass as human. Treat the score as a clue, and never use it alone to accuse a student, a writer or a colleague.
Style statistics need material. Below about 80 words, a single phrase can swing the result, so we refuse to guess. Longer texts (300 words and more) give steadier scores. The maximum is 3,000 words.
The full text is analysed in memory and never saved. The share link keeps only the score, the clues and at most three short excerpts (160 characters each) of the most SI-like sentences, for 7 days.
Yes. Your first 3 checks need no account. A free account then gives you 50 text checks every month, no credit card. Text checks never use credits and are unlimited on Pro and Max. The example texts are always free.
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