Google has secretly been working on a completely new version of its search engine in response to increasing competition from Microsoft's Bing and Facebook's new real-time search engine.
A large team of developers has produced a new infrastructure to provide better search services and the company is after feedback from fellow web developers.
The company said: "For several months, a large team of Googlers has been working on a secret project: a next-generation architecture for Google's web search.
"It's the first step in a process that will let us push the envelope on size, indexing speed, accuracy, comprehensiveness and other dimensions."
The new version looks the same as its current search engine, but the results of searches differ slightly.
The company is getting ready to release the next-generation architecture, while Facebook is releasing a real-time search engine, Microsoft's Bing gains ground and Twitter has becomes a primary source for searching for breaking news.
Some parts of the system aren't completely finished yet, but the new Google search preview is available for users to try out. The company is after feedback on the differences between the old and new systems.
Google said: "Here's how to give us feedback: do a search and look on the search results page for a link at the bottom of the page that says 'Dissatisfied? Help us improve'. Click on that link, type your feedback in the text box and then include the word caffeine somewhere in the text box."