Copyscape

Copyscape is an online plagiarism detection service designed to help individuals and organizations verify whether web content appears elsewhere on the Internet. The service compares text or web pages against content available on the public web to identify copies, near-duplicates, and other matches.

Copyscape offers multiple product tiers and usage options. The basic free checker allows users to paste text or enter a URL to search for duplicates, returning results that show matching pages and a similarity percentage. The paid Copyscape Premium service provides more thorough checks, including higher word counts and expanded search capabilities. An API is also available for developers to integrate plagiarism checking into other applications.

In addition to its core search tools, Copyscape provides Copysentry, a content-monitoring feature that continuously watches the web for copies of specified content and notifies the user when matches are found. This is commonly used by publishers, bloggers, and content owners seeking to protect intellectual property and monitor unauthorized reuse.

Copyscape emphasizes that its results are limited to content indexed on the public web and may not detect all instances of plagiarism, such as content on private or password-protected sites. While widely used for content protection and SEO monitoring, the service may not guarantee detection of every duplication or infringement.

Overall, Copyscape serves as a practical tool for creators, editors, and marketers to verify originality, monitor for copied content, and integrate plagiarism checks into their workflows through its API and monitoring features.