AI Detector: Identify AI-Generated Text in Academic Papers
Our AI detector analyses every sentence individually and accurately flags AI-written content from ChatGPT, GPT-4, Claude, Gemini, Llama & Mistral. Score scale 25–75 · Results in 15 minutes · from $0.29/page. No subscription, no registration.
What Is an AI Detector?
An AI detector is a software tool that analyses text to determine whether it was written by a human or generated by an AI language model such as ChatGPT (OpenAI), Claude (Anthropic), or Gemini (Google). AI detectors measure two core statistical signals: perplexity — how predictable each word choice is given its context — and burstiness — variation in sentence length throughout the document. AI models consistently select high-probability, low-perplexity words; human writers introduce unexpected, idiosyncratic choices that raise perplexity and vary sentence rhythm.
According to research published in Science Advances (Liang et al., 2024), leading AI detectors achieve above 90% accuracy on unedited AI-generated text under controlled conditions. Accuracy varies based on document length, degree of human editing, and the writer's language background. Our PlagAware-powered detector scores every sentence individually on a scale from 25 (human-written) to 75 (AI-generated) — significantly more actionable than single-percentage tools.
How AI Detectors Work
- Measure perplexity (word-choice predictability)
- Analyse burstiness (sentence length variation)
- Score each sentence individually (25–75 scale)
- Detect ChatGPT, Claude, Gemini, Llama & more
- >90% accuracy on unedited AI text (Liang et al., 2024)
How the AI Detector Works
The detector does not produce a single blunt percentage. It evaluates every sentence in your document and assigns an individual AI-probability score, allowing you to identify exactly which passages may be flagged.
Upload Your Document
Submit your academic paper in .docx, .pdf, .txt or other formats. No registration required. Files up to 50 MB are accepted.
Sentence-Level Analysis
PlagAware analyses the statistical language patterns in each sentence — vocabulary distribution, syntactic predictability, perplexity and burstiness — the core signals of AI-generated text.
Score Report by Email
Receive a detailed PDF report within 15 minutes. Every sentence is colour-coded and scored from 25 (human) to 75 (AI), so you know exactly where to look.
What AI Models Are Detected?
Our AI detector covers all major large language models currently in use in academic and professional settings.
OpenAI GPT Family
Detects text generated by ChatGPT (GPT-3.5), GPT-4, GPT-4o and future OpenAI models. The most commonly used AI in academic contexts.
Anthropic Claude
Identifies text from Claude 2, Claude 3 (Haiku, Sonnet, Opus) and Claude 3.5. Known for producing fluent, scholarly-sounding prose.
Google Gemini
Covers Gemini Pro, Gemini Ultra and Bard output. Google's models are increasingly used for research assistance and essay drafting.
Meta Llama
Detects output from Llama 2 and Llama 3. These open-source models are widely deployed in custom AI writing tools and chatbots.
Mistral & Others
Also covers Mistral, Phi (Microsoft), Falcon and other open-weight models. Detection adapts as the AI landscape evolves.
Future Models
The detection engine is continuously retrained. As new LLMs enter the market, coverage is extended — your results stay current.
Understanding the AI Detection Score: 25 to 75
Unlike binary detectors that simply say "AI" or "not AI", our system assigns every sentence a numeric score between 25 and 75.
A score of 25 indicates text that is highly characteristic of human writing — varied vocabulary, irregular sentence rhythm, personal voice. A score of 75 indicates text that carries the statistical hallmarks of AI generation: high predictability, low perplexity, uniform sentence construction.
Scores in the middle range (around 40–55) represent ambiguous cases — AI-assisted writing, heavily edited AI text, or human writing that happens to be unusually formal.
- Score 25–35: Strongly human-written
- Score 40–55: Mixed or ambiguous signals
- Score 65–75: Strongly AI-generated
- Every sentence scored individually
Transparent Pricing — Pay Only for What You Scan
No hidden fees. No subscription. Charged per page (1,800 characters). Minimum order $0.90.
Plagiarism check against 70+ billion sources
- 70+ billion sources
- Results in 15 minutes
- PDF report with sources
- PlagAware technology
Combo: Plagiarism + AI
Both checks together — best value
- Everything in Plagiarism Scan
- AI detection for every sentence
- Detects ChatGPT, Claude, Gemini & more
- Best price per page
AI Scan
AI detection sentence by sentence
- Score scale 25–75
- All major LLMs detected
- Results in 15 minutes
- PDF report by email
Frequently Asked Questions About Our AI Detector
Our AI detector uses PlagAware technology, which scores each sentence on a scale from 25 (human-written) to 75 (AI-generated). This granular, sentence-level approach is significantly more accurate than tools that give a single overall percentage, because it pinpoints exactly which passages are flagged rather than averaging the entire document.
The detector identifies text generated by ChatGPT (GPT-3.5 and GPT-4), Claude (Anthropic), Gemini (Google), Llama (Meta), Mistral, and other major large language models. The underlying detection model is continuously updated as new AI systems are released.
Basic synonym substitution is increasingly ineffective against modern AI detectors. Our system analyses statistical language patterns — word choice distributions, sentence rhythm, syntactic predictability — rather than looking for verbatim AI output. Heavily paraphrased AI text may score lower, but characteristic patterns often remain detectable.
Results are delivered to your email address within 15 minutes in most cases. During peak times processing may take a few hours, but never longer than 24 hours.
Yes. Your uploaded document is never added to any public database. Files are stored on German servers and automatically deleted 14 days after upload. Results are deleted after 28 days. No data is shared with third parties.
Ready to Check Your Paper?
Professional plagiarism check and AI detection — from €0.29/page, results in 15 minutes.
Start Check Now