Paste your text and get a 0-100 ChatGPT-probability score, sentence-level highlights of GPT-fingerprinted phrasing, and a Humanization Score that tells you how natural the text reads. Tuned for GPT-3.5, GPT-4, and GPT-4o output.
No credit card · No signup for your first scan · Up to 99.2% accuracy in our internal benchmark
Paste your draft, upload a PDF or DOCX, or point at a URL. We score it against GPT-3.5, GPT-4, and GPT-4o fingerprints — and ship a one-click humanizer in the same scan to rewrite the flagged sentences.
Open the ChatGPT Detector →Drop text directly, upload a PDF or DOCX file, or paste a URL. Anything under 5,000 characters runs free. Larger drafts run on paid plans.
50+ language signals — burstiness, perplexity, lexical patterns, and structural markers — tuned to recognize GPT-3.5, GPT-4, and GPT-4o output. Updated as new ChatGPT versions ship.
You get an overall AI-probability score, a Humanization Score, sentence-level highlights ranked by suspicion, and a built-in humanizer that rewrites only the flagged sentences.
Run your draft before submission. See which sentences look AI-generated and rewrite them in the same scan — without uploading to a third-party humanizer first.
Check guest posts and ghostwritten drafts before publishing. The Humanization Score gives you a measurable benchmark to track improvements as you rewrite.
Sentence-level highlights give you specific evidence to discuss with students — not a single overall score that's hard to defend.
Bulk-scan deliverables before they ship. API access on the Business plan ($29.99/mo) covers 10,000 calls/mo — about 6× cheaper than Originality.ai's Enterprise tier.
Up to 99.2% accuracy in our internal benchmark against GPT-3.5, GPT-4, and GPT-4o outputs. Results may vary with content type, writing style, model version, and editing level. AI detection is probabilistic — no detector is perfect, and we publish our caveats openly.
What works well: long-form English text (100+ words), unedited or lightly edited ChatGPT output, and content generated through the official OpenAI APIs or the ChatGPT web app.
Where to be cautious: short snippets (under 50 words), heavily human-edited ChatGPT output, custom-fine-tuned GPT models, non-English languages, and code (we don't currently detect AI-written code). We flag low-confidence scores in the result so you know when not to rely on them.
TextSight scores your text against signals trained on GPT-3.5, GPT-4, and GPT-4o output. It returns an overall ChatGPT-probability score (0-100), sentence-level highlights ranked by suspicion, and a Humanization Score that tells you how natural the text reads. The scan typically completes in under three seconds.
Yes. The detector is tuned to recognize the lexical and structural fingerprints of GPT-3.5, GPT-4, and GPT-4o output. We update the training set as new ChatGPT model versions ship. Custom-fine-tuned ChatGPT models or heavily edited output may score lower confidence — we flag those cases.
Yes. The free tier gives you 3 scans per day with the same detector and Humanization Score as the paid plans. No credit card and no signup are required for your first scans. Higher daily limits start at $9.99/mo on the Starter plan.
Up to 99.2% accuracy on our internal benchmark of GPT-3.5, GPT-4, and GPT-4o outputs. Results may vary with content type, writing style, model version, and editing level. AI detection is probabilistic — read /accuracy-methodology for our test setup, false-positive rate, and the caveats we apply to every score.
The ChatGPT detector is tuned to fingerprint OpenAI-specific patterns. Text from Claude, Gemini, or Llama will usually score AI-positive on the general detector but is less likely to score positive on the ChatGPT-specific score. For multi-model detection, use the general AI Detector page.
The detector is most accurate on unedited or lightly edited ChatGPT output. Heavy human editing can push the AI score down — sometimes legitimately, sometimes hiding the original source. Sentence-level highlights show you which specific sentences still read as AI-generated even after editing, so you can use those as evidence.
The detector is tuned for natural-language prose, not source code. Code detection requires different signals (syntactic patterns, comment style, idiom recognition) than what we run. We don't currently ship a code-AI detector.
The general AI Detector scores across all four major model families — OpenAI, Anthropic, Google, and Meta — and surfaces an overall AI probability. This ChatGPT-specific page focuses the same engine on OpenAI signals, which is what you want when you specifically need to flag GPT-written content (the most-used commercial AI for writing).
Detect GPT-written text. Fix what's flagged. One tool. 3 free scans/day.