As AI writing tools become mainstream, distinguishing between human and machine-generated text is increasingly important — for educators, publishers, employers, and content teams alike.
An AI text detector automates this process, scanning text for the linguistic fingerprints left behind by large language models (LLMs).
How AI Text Detection Works
Modern AI text detectors use two primary approaches:
1. Statistical Analysis (Perplexity & Burstiness)
- Perplexity: Measures how “surprising” each word choice is. AI text is statistically predictable; humans take more unexpected linguistic turns.
- Burstiness: Humans naturally vary sentence length dramatically. AI models produce more uniform, consistent sentence structures.
2. Machine Learning Classification
Trained on large datasets of both human-written and AI-generated text, classification models learn to recognize subtle patterns invisible to the human eye — including token probability distributions, syntactic patterns, and semantic uniformity.
Which AI Models Does It Detect?
Our AI text detector identifies content from all major language models:
- OpenAI: GPT-3.5, GPT-4, GPT-4o, GPT-4 Turbo
- Anthropic: Claude 2, Claude 3 (Haiku, Sonnet, Opus)
- Google: Gemini 1.0, Gemini 1.5, Gemini Ultra
- Meta: Llama 2, Llama 3
- Mistral AI: Mistral 7B, Mixtral
- Others: Cohere, Yi, Qwen, and more
Who Uses AI Text Detectors?
| User Type | Use Case |
|---|---|
| Teachers | Verify student essay authenticity |
| Publishers | Ensure content meets editorial standards |
| Recruiters | Validate writing samples from candidates |
| SEO teams | Audit content before publishing |
| Researchers | Screen papers and submissions |
| Platforms | Moderate user-generated content at scale |
Tips for Accurate Results
- Submit longer text: Detection accuracy improves significantly with 200+ words
- Test original drafts: Heavily edited text is harder to classify correctly
- Use as one signal: Combine with other evidence; no detector is 100% accurate
- Check multiple times: If a score is borderline, try analyzing specific sections separately
Frequently Asked Questions
How long should the text be for accurate detection? We recommend at least 150–200 words. Shorter texts produce less reliable results due to limited statistical signal.
Can AI-generated text always be detected? No detector achieves 100% accuracy. Heavily paraphrased, edited, or humanized AI text becomes progressively harder to identify. Detection is a signal, not a verdict.
Does it work on non-English text? Currently optimized for English. Other languages may produce less reliable results.
Is my text private? Yes. We do not store, log, or share submitted text.