Local search is the natural evolution of "yellow pages" directory advertising moving to the internet. Some of the local search data used on-line comes from yellow page publishers. Telephone directories still attract a significant amount of advertising, though this has recently lost ground to internet local search. A variety of search engines are currently providing local search, including efforts backed by the largest search engines, and new start-ups. Some of these efforts are further targeted to specific vertical segments, and several are tied into mapping products.

On the World Wide Web, local search is a search engine that allows for geographically constrained searching. The query includes not only information about "what" the site visitor is searching for (such as keywords, a business category, or the name of a consumer product) but also "where" information, such as a street address, city name, postal code, or geographic coordinates like latitude and longitude. These sites are primarily supported by advertising, but some accept payments from retail merchants and others wishing to be listed.

Various geolocation techniques may be used to match visitors' queries with information of interest. The type of information and points of interest returned varies with the type of local search engine. Some sites, such as superpages.com (owned by Idearc Media) and TrueLocal), list local businesses, typically in a categorization scheme similar to (or actually derived from) a traditional Yellow Pages phone book.

Google Maps (formerly Google Local) looks for physical addresses mentioned in regular web pages. It provides these results to visitors, along with business listings and maps. Product-specific search engines, such as Google Product Search, Yokel.com and uCan Health use techniques such as targeted web crawling and direct feeds to collect information about products for sale in a specific geographic area. Other local search engines adjunct to major web search portals include general Windows Live Local, Yahoo! Local, and ask.com's AskCity.

Traditional media companies, including newspaper publishers and television and radio broadcasters, are starting to add local search to their local websites in an effort to attract their share of local search traffic and advertising revenues in the markets they serve. These local media companies either develop their own technology and data, or purchase "private label" services from a local search company.

Several providers have been experimenting with providing local search for mobile devices. Some of these are location aware. Google currently provides an experimental voice-based locative service (1-800-GOOG-411). Many mobile web portals require the subscriber to download a small Java application, however the recently added .mobi top level domain has given impetus to the development of mobile targeted search sites such as Yumm that are based upon a standard mobile specific XML protocol that all modern mobile browsers understand. The advantage is that no software needs to be downloaded and installed, plus these sites may be designed to simultaneously provide conventional content to traditional PC users by means of automatic browser detection.

Electronic publishers (such as businesses or individuals) with information they would like to appear on local search engines have several options. Business listing information can be distributed via the traditional Yellow Pages, electronic Yellow Pages aggregators, direct contact with the local search engines (such as through Google Base), or search engine optimization services. Some search engines will pick up on web pages that contain regular street addresses displayed in machine-readable text (instead of a picture of text, which is more difficult to interpret). Web pages can also use GeoTagging techniques.