AI Content Detector

Quick answer: An AI content detector estimates how likely it is that text was written by a chatbot such as ChatGPT, Gemini or Claude. This free one scores English text, highlights the sentences that read most like AI and lists the patterns and words behind the score. No detector can prove who wrote something, so treat the score as a hint.

What is an AI content detector?

An AI content detector is a tool that reads a piece of writing and estimates whether a person or an AI model wrote it. Teachers use one to review assignments, editors to check freelance articles, and writers to make sure their own drafts don’t sound robotic before they publish.

No detector can prove authorship. What a detector can do is spot habits that chatbots fall into far more often than people: stock phrases, tidy lists of three, signposting like “In this guide you’ll learn”, and sentences of nearly the same length. This tool shows you every signal it found, so you can judge the result yourself instead of trusting a single number.

How do I check if text is AI-generated?

1. Paste English text into the box, or press Paste. You need at least 40 words, and 150 or more gives a steadier result. Press Try sample to see a scan first.
2. Press Scan text, or Ctrl+Enter (⌘+Enter on a Mac).
3. Read the score ring and the verdict, then the AI, Mixed and Human split.
4. Look at your text. Sentences in yellow are likely AI, and sentences in purple are mixed.
5. Open the AI sentences, AI patterns and AI vocab tabs to see why. Click a sentence in the list to jump to it.
6. Press Edit text to change the flagged parts, then scan again.

What the result shows

Hover over a highlighted sentence to see its own score, such as “98% AI-like”.

Worked example: the built-in sample

Press Try sample and the tool scans a 79-word text. Its first paragraph is written in stock chatbot style (“In today’s fast-paced digital landscape, productivity tools play a crucial role…”). The second is a short personal note (“I tried six of these apps last month. Two crashed on my old laptop.”).

• Score: 73%, “most likely AI generated”.
• Split: AI 61%, Mixed 0%, Human 39%. The three chatbot-style sentences score 98% to 99% each. The three personal sentences score 30% to 37%.
• Patterns found: hedged filler (2 sentences), a list of three, a formal opener (“Moreover”) and a “not just X, but Y” contrast.
• AI vocab found: 7 items, including “landscape”, “crucial”, “foster”, “seamless” and “it’s important to note”.
• Sentence variety: Medium (0.41).

This is how most real texts look: a mix. The split tells you where to look, which matters more than the headline number.

How does this AI detector work?

The detector splits your text into sentences and scores each one from 0 to 100% using visible rules, not a trained AI model. It looks at four kinds of signal.

1. AI writing patterns

Each sentence is checked once for nine patterns:

• Signposting, such as “In this guide”, “Let’s explore” or “Here’s how”.
• Promises of what you will learn, such as “You’ll discover” or “Everything you need to know”.
• A list of three or more items.
• A colon reveal, such as “Here is the update: …”.
• “Not just X, but Y” contrasts.
• Formal openers: Moreover, Furthermore, Additionally, However, Overall, Thus, Hence and similar.
• Honesty claims, such as “The truth is”, “Simply put” or “In short”.
• Hedged filler, such as “it’s important to note”, “plays a key role” or “a wide range of”.
• Em dashes.

2. AI vocabulary

The tool carries a list of about 70 words and 30 phrases that chatbots use far more than people do, such as “delve”, “tapestry”, “seamless”, “robust”, “pivotal”, “foster”, “elevate”, “unlock”, “landscape” and “realm”. Each one found raises that sentence’s score.

3. Sentence variety (burstiness)

People mix short, punchy sentences with long ones. Chatbots tend to write sentences of similar length, one after another. The tool measures this spread across your whole text: low variety pushes every sentence’s score up and high variety pulls it down. Very short sentences (under 6 words) also lower a score, while tidy mid-length ones (14 to 35 words) raise it a little.

4. Human habits

Some things lower a sentence’s score: slang such as “tbh”, “gonna” or “yaar”, double “!!” or “??”, trailing dots, a sentence that starts in lower case, emoji, and first-person words like “I” and “my”.

Because the rules are fixed and visible, the tool is good at catching stock chatbot phrasing and easy to fool with a light human edit. It is built for English only. Hindi and other languages don’t trigger the English patterns or word list, so their score comes from sentence length alone and means very little.

How accurate are AI content detectors?

No AI detector is reliably accurate, including paid ones. Every detector makes two kinds of mistake: it flags human writing as AI (a false positive), and it misses AI writing that has been edited or prompted to sound casual (a false negative). The research is clear on this.

• OpenAI shut down its own detector. OpenAI’s AI text classifier caught only 26% of AI-written text in its own tests and wrongly flagged human text 9% of the time. OpenAI withdrew it on 20 July 2023, “due to its low rate of accuracy”.
• Detectors are biased against non-native English writers. A Stanford study published in the journal Patterns in 2023 ran seven popular detectors on 91 TOEFL essays written by non-native English students. The detectors wrongly marked 61.22% of them as AI-generated, and 18 of the 91 were flagged by all seven detectors. Essays by US eighth-graders were classified almost perfectly. The authors also found that simple prompting could get AI text past the detectors, and cautioned against using them in education.

We tested our own tool the same way. A leave application we wrote by hand in formal Indian office English (“Furthermore, I have completed all pending reports… Additionally, Mr. Verma has agreed to handle my daily tasks, client calls, and email follow-ups”) scored 43%, “partly AI generated”. Formal connectors and lists of three are normal in Indian office writing, and they are exactly what the tool counts. In the other direction, rewriting just the three chatbot sentences of the sample in plain words dropped it from 73% to 41%.

Commercial detectors publish much higher accuracy figures. GPTZero’s homepage, for example, claims 99.9% accuracy from the company’s own testing. Those are the companies’ own claims, and their tests don’t always match your kind of writing.

What do the scores mean?

The split pills show a different number from the ring. A 500-word article can score 70% overall with one fully human paragraph in it, and the split makes that visible.

How this tool compares with GPTZero and ZeroGPT

Details for GPTZero and ZeroGPT are from their own homepages in October 2026 and can change. If you need a second opinion, run the same text through two tools. If they disagree, that tells you the text is a borderline case.

How can I make my writing sound less like AI?

• Cut the signposts. Drop “In this guide, you’ll learn” and “Let’s dive in”. Start with the answer.
• Vary sentence length. Follow a long sentence with a short one. Like this.
• Use plain words. “Use” instead of “leverage”, “look at” instead of “delve into”, “smooth” instead of “seamless”.
• Add what only you know. A real example, a number you measured, a mistake you made, a local detail. A chatbot can’t invent your experience.
• Break the rule of three. Not every list needs three items. Sometimes two is enough.

Check length limits after you edit with our word counter. If you’re comparing which chatbot writes most naturally, see our ChatGPT vs Gemini vs Claude test, and for pictures rather than text, read how to detect AI-generated images.

Should teachers use AI detectors on assignments?

Use a detector as a reason to talk, never as proof. The Stanford researchers advised against using detectors in evaluative or educational settings, and students who write in English as a second language are the most likely to be wrongly flagged. If a score worries you, ask for drafts, notes or the document’s version history, talk to the student about how they wrote it, and compare it with their earlier work. For tools students can use honestly, see our list of free AI tools for students in India.

Is my text private?

Yes. The detector runs entirely in your browser with JavaScript. Your text is not uploaded, stored on our server, or used to train any AI model. Once the page has loaded, you can switch off your internet connection and still scan text. Closing the tab clears everything.

Key facts

• OpenAI’s AI text classifier correctly identified 26% of AI-written text and wrongly labelled human text as AI 9% of the time, and was withdrawn on 20 July 2023 for its low accuracy. (Inquirer Technology (opens in new tab), Search Engine Journal (opens in new tab))
• Seven GPT detectors wrongly classified 61.22% of 91 TOEFL essays by non-native English writers as AI-generated, and all seven flagged 19% of them. (Stanford HAI (opens in new tab))
• The same study found that simple prompting strategies could both reduce this bias and get AI text past the detectors, and its authors cautioned against using detectors in educational settings. (Liang et al., 2023 (opens in new tab))
• GPTZero says no AI detector is 100% accurate and that results should not be the final verdict, while longer texts give more reliable results. (GPTZero (opens in new tab))