This is part one of a two-part article covering the current state of web search APIs. Please be sure to check out part two.
For years, Google and Yahoo dominated the search engine market providing web search tools that help users quickly and easily find information for just about anything. Then in May 2009 along came Microsoft Bing, a new approach to internet search aimed at simplifying, organizing, and expanding web search experiences for users. About 14 months later, Microsoft Bing overtook Yahoo for the first time in the U.S., the browser edging past Yahoo, but still a very distant second place when compared to Google.
Google, Microsoft, and Yahoo have been providing web search APIs for developers for quite some time. Many developers have been relying on, and still rely on, the APIs provided by these companies to power the web search and/or site search capabilities of websites and blogs. Today, Google, Microsoft, and Yahoo continue to provide web search tools for developers; however, in the past few years, all three companies have made significant changes regarding the web search tools/APIs they provide.
A Number of Web Search APIs Have Been Shut Down
Google and Yahoo have shut down a number of web search APIs in recent months. In February of this year, Google shut down five web search APIs which included the Google Blog Search API, Google News Search API, Google Image Search API, Google Video Search API, and Google Patent Search API. Google also recently restricted access to the unpublished Google autocomplete API advising developers to use Google Custom Search Engine (CSE) instead.
In March of this year, Yahoo shut down the BOSS JSON Search API advising developers that they can use the Yahoo Partner Ads (YPA) service to add algorithmic web results along with Yahoo search ads to websites and blogs.
Same Players, Different Web Search Tools for Developers
Google provides two general web search tools for developers; Google CSE and Google Site Search. Google CSE can be used by developers to add web search and/or site search functionality to a website, blog, or collection of websites. Google Site Search is a feature-packed solution for adding only site search functionality to websites and blogs. Google also recently released the Google Knowledge Graph Search API (read-only), a separate search API allowing programmatic access to Google's Knowledge Graph.