Check if text was written by AI or a human
Enter text on the left and run the tool to see results here.
AI detector tool online with PDF Workspace — instantly check whether any text was written by AI (ChatGPT, Claude, Gemini, etc.) or by a human, with confidence scores and sentence-level breakdowns. The AI detector uses Claude Sonnet 4.5 trained on AI vs human writing patterns to spot telltale signals like vocabulary uniformity, sentence-length cadence, transition word overuse, and stylistic flatness. Perfect for educators screening student essays, editors verifying freelance submissions, recruiters checking AI-assisted cover letters, or publishers vetting article submissions. The AI detector provides a percentage AI-probability score plus a sentence-by-sentence highlight showing exactly which passages look AI-generated and which look human. Supports 50+ languages with the same accuracy. Free for 3 detections per day on guest accounts, 50 on Pro, unlimited on Business. Text is processed privately, auto-deleted in 24 hours, never used to train AI.
Paste text into the editor, or upload a PDF/.docx. The AI detector handles up to 10,000 words per scan.
Click Detect — analysis completes in 5-15 seconds with AI probability score and sentence-level highlights.
See AI-probability per sentence color-coded. Export the report as PDF for record-keeping.
Teachers run essays through the AI detector to flag suspected AI-generated submissions for academic integrity review.
Editors check freelance article submissions to ensure original human writing, not AI-assisted output.
Recruiters scan candidate cover letters to identify generic AI-generated text vs personalized human writing.
How AI Detector on PDF Workspace compares to the most common alternatives.
| Feature | PDF Workspace | iLovePDF | Smallpdf |
|---|---|---|---|
| Detection accuracy | 95-98% | No AI detector | No AI detector |
| Sentence-level breakdown | Color-coded per sentence | N/A | N/A |
| Languages supported | 50+ | N/A | N/A |
| Free daily limit | 30 operations/day (guest), unlimited on Business | ~3 tasks/hour for free, premium starts $7/mo | 2 documents/day free, premium $9/mo |
| Max file size (free) | 5 MB free, 100 MB Pro, 500 MB Business | ~10 MB free | ~5 MB free |
| AI features included | 12 AI tools (Ask PDF, Summarize, Translate, etc.) | Limited — AI add-on only on premium | AI features locked behind premium tier |
| Privacy / data handling | TLS 1.3 + AES-256, auto-delete in 24h, no model training | Files deleted in 2h, standard SSL | Files deleted in 1h, ISO 27001 |
| No watermark on output | Always — free + paid | Free tier may add watermark | Free tier may add watermark |
The AI detector achieves 95-98% accuracy on benchmark datasets, with sentence-level resolution. Very short texts (<200 words) have lower accuracy due to limited sample size.
Yes. The detector identifies text from major LLMs including ChatGPT (3.5/4/4o), Claude (Sonnet/Opus), Gemini, Llama, and Mistral models.
Sophisticated humanization (like our Humanize tool) can reduce detection rates, but skilled detectors still catch ~70% of humanized content. Check both tools for context.
Yes. The AI detector supports 50+ languages with consistent accuracy across major languages.
The detector analyzes statistical patterns (vocabulary entropy, sentence-length variance, perplexity, transition usage) that differ between AI and human writing.
False positives occur ~2-5% of the time, especially on formulaic writing (legal templates, technical docs). Always review flagged content manually before acting.
No. Text is analyzed in-memory and auto-deleted within 24 hours. We never train models on user data.
3 scans per day on guest and free accounts. Pro gets 50/day, Business unlimited. No credit card for any tier.
Translates your PDF content into another language while keeping formatting.
Condenses long documents into clear and concise readable summaries.
Highlights all differences between two PDF versions side by side.
Converts multiple image files into a single organized PDF document.
