In mathematics and computer science, operators are characters or sequences of characters that represent an action or cause an action to be performed. Boolean operators are commonly used in search. AND, for example, indicates that Web pages in the results must contain both the word or phrase preceding it and the word (or phrase) following it. NOT indicates that pages in search results should not contain the word or phrase after it. OR indicates that the pages in search results should include any of the terms on either side in the query rather than pages that contain both or all terms.
Other search operators are usually placed directly in front of a query word or phrase, with no intervening space. Multiple operators can be combined in a query to further narrow the focus of a search.
Here are a few examples of advanced Google search operators:
- site: followed (without a space) by a website or domain returns files located there.
- filetype: followed by a file extension returns files of the specified type, such as DOC, PDF, XLS and INI. Multiple file types can be searched for simultaneously by separating extensions with “|”.
- inurl: followed by a particular string returns results with that sequence of characters in the URL.
- intext: followed by the searcher’s chosen word or phrase returns files with the string anywhere in the text.
Search operators can be combined in a search query to fine-tune a search. A complex search engine query is sometimes referred to as a Google dork query, is sometimes used to find information that is not purposefully made available by a site owner. The practice, also known as Google hacking, is often recommended as a way to discover site vulnerabilities that need attention.
In this video, Andreas Johansson demonstrates how to use Google search operators: