Google has been playing around with different homepage designs and running live tests over the past few months.
In , Google said it had tried 10 different versions of the fade in design before settling on the one that has gone live.
Writing in the blog, Marissa Mayer, vice-president of search products and user experience, Kris Hom, software engineer, and Jon Wiley, user experience designer, said: "Like the new supersized search box we launched several months ago, this change is one that is very noticeable at first, and then quickly becomes second nature. We hope you like it."
Google is also reported to be planning to launch an online property portal and is in talks with UK estate agents including Douglas & Gordon and Savills.
The Financial Times reports that the service could post a threat to existing online property sites, such as Rightmove. If the UK version is based on the property site launched by Google in the US and Australia, it would let estate agents list properties for free, and tie in with the Street View service.
Separately, Microsoft has effectively abandoned plans to pay online news publishers to remove content from Google's news aggregator, with Staya Nadella, senior vice-president for online services, saying that the company was not focused on getting non-Google content.
Details of the plan emerged after Rupert Murdoch said that News Corp newspapers would block access to Google News after a paywall was erected around the sites next year.