ContentDetector.org

ContentDetector.org is a free tool that estimates how much text may be AI-written and how much may be human-written. Users can paste text, upload a file, or submit a URL to receive a report with a score, highlighted sections, and review guidance. The site says its detector evaluates patterns such as token predictability, repeated meaning, formatting consistency, and localized stretches of uniform phrasing. It also assesses patterns associated with GPT-5, Gemini, Claude, and other large models. A separate converter rewrites AI-generated text to adjust tone, flow, clarity, and sentence variety; its input counter is 1000 characters. Other options include API access, document uploads, and bulk checks of folders or URL lists. Platforms listed are web, browser extension, iOS, macOS, and Windows. The site says inputs are not used to train models and describes retention controls; its FAQ says inputs are kept only as needed to create a report and removed when the tab closes. The converter page says submissions are processed instantly and not stored. Results can be wrong, particularly for very short or heavily edited text, so the site recommends human review.

ContentDetector.org combines AI-writing estimates with reports, bulk options, and a text converter. Its own caveat matters: detection results may be wrong, so they should not replace human review.

The site identifies publishers and SEO teams, agencies, educators, and learning-and-development teams as intended users. It may suit people who want detection reports or a short-text rewriting tool, provided they review detection results themselves.

ContentDetector.org is a writing checker that estimates AI authorship and rewrites AI-generated text. It suits publishers, SEO teams, agencies, educators, and learning-and-development teams that want free screening and a compact converter. The combination is useful for initial review, but the detector’s own warning rules out treating its score as a verdict.

Overview

Users can paste text, upload a file, or submit a URL and receive an estimated percentage of AI-written versus human-written content. Reports add section highlights and review guidance, giving an editor places to look more closely instead of leaving them with a single number. The site warns that results can be wrong, especially on very short or heavily edited text, so the report is best used to guide human review.

ContentDetector.org says its scoring considers token-pattern predictability, semantic repetition, formatting regularity, and local bursts of uniform phrasing. It evaluates patterns associated with GPT-5, Gemini, Claude, and other large models. That range may be useful for broad screening, but it does not make the score proof of authorship.

Key features

Detection and reports

The percentage score, passage-level highlights, and guidance make the detector more useful to editorial teams than a bare classification. They can help prioritize review across submissions or pages. The caveat is material for educators and anyone making consequential decisions: the site itself advises human review, and short or substantially edited writing is especially prone to error.

Converter and bulk checks

The AI-to-human converter rewrites text to improve tone, flow, clarity, and sentence variety. Its 1,000-character input counter makes it a short-form tool; users with longer passages will need to work within that limit. The homepage also describes document uploads, API connections, and bulk checks on folders or URL lists, which better suit teams screening multiple items than someone checking only an occasional paragraph.

Privacy and support

The homepage says inputs are not used to train models and that workspace settings let users control retention. Its FAQ says inputs are kept only as needed to generate a report and removed when the tab closes. The converter page separately says submitted content is processed instantly and never stored. Support is offered through email, phone, and a contact form, with the team saying it will respond as soon as possible.

Pricing

The Free plan costs nothing and includes AI content detection and the AI text converter, with converter input capped at 1,000 characters. There is no paid tier to weigh against it in the plan described here, so it is a straightforward choice for occasional checks and short rewrites. Teams considering regular bulk or API use should account for their needs before relying on a free plan whose stated terms do not give a detection quota or seat count.

API access, a browser extension, and batch scanning are available. These options make the product more relevant to teams with repeat workflows, though the free plan’s published details do not establish how much detection or bulk use it allows.

Platforms

ContentDetector.org is available on the web, as an extension, and on iOS, macOS, and Windows. Its broad platform range gives individuals and distributed teams multiple ways to access it, while API access supports integration into other workflows.

Who it's for

This is a practical starting point for publishers, SEO teams, agencies, educators, and learning-and-development teams that need a free first-pass detector with report guidance. Bulk scanning and API access may fit teams reviewing many documents or URLs. It is a poor fit when a score must establish authorship, or when a long-form rewrite is central to the workflow: the site cautions against relying on detection alone, and the converter accepts only 1,000 characters.

Pros and cons

• Useful report context: Section highlights and review guidance give editors more direction than an overall AI-versus-human percentage by itself.
• Flexible inputs: Pasted text, files, and URLs support several common screening workflows.
• Free detection and converter: The Free plan includes both, making it accessible for occasional checks without a subscription.
• Team workflow options: API access, a browser extension, and batch scanning can support repeat use across teams.
• Short converter limit: The 1,000-character cap constrains its usefulness for rewriting longer passages.
• Scores require judgment: The site warns that results can be wrong, particularly for short or heavily edited text, limiting its value as standalone evidence.

Alternatives

TrustOriginality.ai is another option for readers who want a free plan with one text analysis per month or a €4.99 monthly Quick Check plan with three multimodal verifications per month and three API calls.

GPTZero may suit readers who want a free allowance of 10,000 words per month and 50,000 characters, or an Essential plan at $8.33 a month when paying annually.

AI Detectors.io is an alternative with a free plan and support for API, extension, macOS, web, and Windows.

It's AI offers a free plan that includes 4,000 words, file upload, three deep scans, and a Chrome extension.

Originality.ai offers a no-subscription Basic option with AI detection, three scans per day, and a 2,000-word limit per scan.

Winston AI is a paid product with a free 14-day trial that includes 2,000 credits, AI content and image detection, document and OCR scanning, and email and chat support.

AI Detector Pro offers a free plan with three AI scans per month and no humanizations.

Detecting-AI.com is another free option for readers who want a no-account-required check with a 15,000-character limit per check.

For more options, see AI Content Detectors.

Verdict

Choose ContentDetector.org for free first-pass checks across text, files, or URLs, especially if report highlights, bulk scanning, or a short converter fit your workflow. Its breadth of inputs and team tools are the main reasons to pick it. Look elsewhere if you need a longer rewrite allowance or a detector score you can treat as definitive; ContentDetector.org explicitly calls for human review.