AI Text Detector — Free Online AI Writing Checker
Paste any text to analyze it for AI-writing patterns — vocabulary density, sentence variation, and more. Runs entirely in your browser, no account needed.
Heuristic analysis — not a classifier
Results are based on statistical patterns. Human writers can score high; AI can be edited to score low. Use this as a signal, not a verdict. No text is sent anywhere — analysis runs locally in your browser.
How it works
Four statistical properties are scored and weighted to produce an overall AI likelihood estimate:
- 📚AI vocabulary (35%) — words and phrases AI models use disproportionately often: "delve," "nuanced," "pivotal," "seamlessly," "it's important to note," etc.
- 📏Sentence variation (30%) — humans mix short punchy sentences with longer complex ones. AI output tends to be uniform in length (measured as the coefficient of variation across sentence lengths).
- ✂️Contraction usage (25%) — AI writing is typically formal and avoids contractions ("do not" vs "don't"). Frequent contractions suggest human authorship.
- 📝Paragraph uniformity (10%) — AI often produces paragraphs of very similar length. Requires at least 3 paragraphs to score.
Related: Case Converter for text formatting, or JSON Formatter for data cleanup tasks.
Frequently Asked Questions
Is the AI Text Detector free?
Yes — completely free. No account and no data sent to a server.
Is my text uploaded anywhere?
No. Detection runs entirely in your browser using heuristic analysis. Your text never leaves your device.
Do I need an account?
No account, no login, and no signup required.
How accurate is the detector?
The detector uses statistical heuristics — AI vocabulary frequency, sentence length variation, contraction usage, and paragraph uniformity — not a language model. It identifies patterns common in AI-generated text but cannot make a definitive determination. A high score is a strong signal, not a certainty.
Can AI-generated text score low?
Yes. AI text that has been heavily edited by a human, or that was written with deliberate effort to vary sentence structure and use contractions, can score lower. The detector catches patterns in unedited AI output most reliably.
How much text do I need for an accurate result?
At least 200–300 words produces a reliable score. Very short passages lack enough sentences and paragraphs for the sentence variation and paragraph uniformity signals to be meaningful.