Search as you type. It’s a simple and straightforward idea—people can get results as they type their queries. Imagining the future of search, the idea of being able to search for partial queries or provide some interactive feedback while searching has come up more than a few times. Along the way, we’ve even built quite a few demos (notably, Amit Patel in 1999 and Nikhil Bhatla in 2003). Our search-as-you-type demos were thought-provoking—fun, fast and interactive—but fundamentally flawed. Why? Because you don’t really want search-as-you-type (no one wants search results for [bike h] in the process of searching for [bike helmets]). You really want search-before-you-type—that is, you want results for the most likely search given what you have already typed.

As you can imagine, searching even before someone types isn’t easy—which is why we are so excited today to be unveiling Google Instant. Google Instant is search-before-you-type. Instant takes what you have typed already, predicts the most likely completion and streams results in real-time for those predictions—yielding a smarter and faster search that is interactive, predictive and powerful.

Here are a few of the core features in Google Instant:

• Dynamic Results – Google dynamically displays relevant search results as you type so you can quickly interact and click through to the web content you need.
• Predictions – One of the key technologies in Google Instant is that we predict the rest of your query (in light gray text) before you finish typing. See what you need? Stop typing, look down and find what you’re looking for.
• Scroll to search – Scroll through predictions and see results instantly for each as you arrow down.

Here’s a video that explains Google Instant in greater depth:

To bring Google Instant to life, we needed a host of new technologies including new caching systems, the ability to adaptively control the rate at which we show results pages and an optimization of page-rendering JavaScript to help web browsers keep up with the rest of the system. In the end, we needed to produce a system that was able to scale while searching as fast as people can type and think—all while maintaining the relevance and simplicity people expect from Google.

The user benefits of Google Instant are many—but the primary one is time saved. Our testing has shown that Google Instant saves the average searcher two to five seconds per search. That may not seem like a lot at first, but it adds up. With Google Instant, we estimate that we’ll save our users 11 hours with each passing second!

As part of our current rollout, Google Instant will become the core search experience on Google.com for Chrome, Firefox, Safari and IE 8. We’ll also be offering Google Instant to our users in France, Germany, Italy, Russia, Spain and the U.K. who are signed in and have Instant-capable browsers. Over the coming weeks and months, we’ll work to roll out Google Instant to all geographies and platforms.

We’re very excited about today’s announcement and hope that you are too. Give Google Instant a try and let us know what you think!

Posted by Marissa Mayer, VP Search Products & User Experience