ContentDetector.org is a free tool that estimates whether text was written by AI and displays a percentage split between AI-written and human-written content. Users can paste text, upload a file, or submit a URL for a report with a score, section highlights, and review guidance. The site says its detector evaluates signals such as token predictability, repeated meaning, formatting regularity, and localized stretches of uniform phrasing, including patterns associated with GPT-5, Gemini, Claude, and other large models. It also offers a converter that rewrites AI-generated text to improve tone, clarity, flow, and sentence variety; its input counter shows a 1000-character limit. Listed options include API access and bulk checks of folders or URL lists, alongside a browser extension. The site says inputs are not used for model training and describes retention controls; its FAQ says inputs are kept only as needed for a report and removed when the tab closes. The converter page says submissions are processed instantly and not stored. The site warns that results can be wrong, particularly for very short or heavily edited text, and recommends human review.
Who it is for
The site identifies publishers, SEO teams, agencies, educators, and learning-and-development teams as intended users. It may suit people who want a first-pass text estimate with review guidance, rather than a definitive authorship judgment.
What is good
- Accepts pasted text, files, and URLs.
- Reports include scores and section highlights.
- Offers API access and bulk checks.
- Converter input counter shows 1000 characters.
- Available on web, extension, iOS, macOS, and Windows.
What to know first
- Detection can be wrong on short text.
- Heavily edited text may produce wrong results.
- Converter input counter shows a 1000-character limit.
Verdict
ContentDetector.org pairs AI-text estimates with a rewrite converter and several ways to submit content. Treat scores as prompts for human review, especially for short or heavily edited material.
ContentDetector.org plans and pricing
All plansCompared on AI content detectors
- Free plan
- Yes
- API access
- Yes
- Browser extension
- Yes
- Batch scanning
- Yes
