Google Public DNS: 70 billion requests a day and counting

We launched Google Public DNS in December 2009 to help make the web faster for everyone. Today, we’re no longer an experimental service. We’re the largest public DNS service in the world, handling an average of more than 70 billion requests a day.

DNS acts like the phone book of the Internet. If you had to look up hundreds or thousands of phone numbers every day, you’d want a directory that was fast, secure and correct. That’s what Google Public DNS provides for tens of millions of people.

Google Public DNS has become particularly popular for our users internationally. Today, about 70 percent of its traffic comes from outside the U.S. We’ve maintained our strong presence in North America, South America and Europe, and beefed up our presence in Asia. We've also added entirely new access points to parts of the world where we previously didn't have Google Public DNS servers, including Australia, India, Japan and Nigeria.

Shortly after launch, we made a technical proposal for how public DNS services can work better with some kinds of important web hosts (known as content distribution networks, or CDNs) that have servers all of the world. We came up with a way to pass information to CDNs so they can send users to nearby servers. Our proposal, now called “edns-client-subnet,” continues to be discussed by members of the Internet Engineering Task Force. While we work with the IETF, other companies have started experimenting with implementing this proposal.

We’ve also taken steps to help support IPv6. On World IPv6 Day, we announced our IPv6 addresses: 2001:4860:4860::8888 and 2001:4860:4860::8844 to supplement our original addresses, and

Google Public DNS’s goal is simple: making the web—really, the whole Internet!—faster for our users. If you’d like to try it yourself, please see our page Using Google Public DNS. For more information, please see our Introduction to Google Public DNS and Frequently Asked Questions.

Knocking down barriers to knowledge

As much as technology has advanced, there are still many barriers between you and the answers you’re looking for—whether you’re juggling a clunky mobile keyboard or waiting for a website to load. Today we held a media event in San Francisco where we talked about some of the latest things we’re doing to tackle these barriers on mobile, announced that we’re bringing our speech recognition and computer vision technology to the desktop, and took the next step for Google Instant—Instant Pages.

The thirst for knowledge doesn’t stop when you step away from your computer, it continues on your mobile device. In the past two years, mobile search traffic has grown five-fold. Mobile search today is growing at a comparable pace to Google in the early years.

Here you can see that mobile search traffic growth over the past three years (the red line) is comparable to overall Google search traffic growth over the same duration (the blue line) but earlier in our history.

One of the technologies driving this growth is speech recognition. With Voice Search, you don’t have to type on a tiny touchscreen. You can just speak your query and the answer is on the way. We’ve invested tremendous energy into improving the quality of our recognition technology—for example, today we teach our English Voice Search system using 230 billion words from real queries so that we can accurately recognize the phrases people are likely to say. As the quality has increased, so has usage: in the past year alone, Voice Search traffic has grown six-fold, and every single day people speak more than two years worth of voice to our system.

We first offered speech recognition on mobile search, but you should have that power no matter where you are. You should never have to stop and ask yourself, “Can I speak for this?”—it should be ubiquitous and intuitive. So we've added speech recognition into search on desktop for Chrome users. If you’re using Chrome, you’ll start to see a little microphone in every Google search box. Simply click the microphone, and you can speak your search. This can be particularly useful for hard-to-spell searches like [bolognese sauce] or complex searches like [translate to spanish where can I buy a hamburger]. Voice Search on desktop is rolling out now on in English, but in the meantime you can check it out in our video:

Searching with speech recognition started first on mobile, and so did searching with computer vision. Google Goggles has enabled you to search by snapping a photo on your mobile phone since 2009, and today we’re introducing Search by Image on desktop. Next to the microphone on, you’ll also see a little camera for the new Search by Image feature. If you click the camera, you can upload any picture or plug in an image URL from the web and ask Google to figure out what it is. Try it out when digging through old vacation photos and trying to identify landmarks—the search [mountain path] probably isn’t going to tell you where you were, but computer vision may just do the trick. Search by Image is rolling out now globally in 40 languages. We’re also releasing Chrome and Firefox extensions that enable you to search any image on the web by right-clicking.

Whether you type, speak or upload a photo, once you’ve indicated what you’re looking for the next step in your search is to sift through the results and pick one. To make this faster, last year we introduced Google Instant, which gives you search results while you type. We estimated Google Instant saves you between two and five seconds on typical searches. But once you’ve picked a result, you click, and then wait again for the page to load—for an average of about five seconds.

We want to help you save some of that time as well, so today we took the next step for Google Instant: Instant Pages. Instant Pages can get the top search result ready in the background while you’re choosing which link to click, saving you yet another two to five seconds on typical searches. Let’s say you’re searching for information about the Smithsonian Folklife Festival, so you search for [dc folklife festival]. As you scan the results deciding which one to choose, Google is already prerendering the top search result for you. That way when you click, the page loads instantly.

Instant Pages will prerender results when we’re confident you’re going to click them. The good news is that we’ve been working for years to develop our relevance technology, and we can fairly accurately predict when to prerender. To use Instant Pages, you’ll want to get our next beta release of Chrome, which includes prerendering (for the adventurous, you can try Instant Pages today with the developer version). It’s one more step towards an even faster web.

To learn more about today’s news, visit our new Inside Search website at There you’ll find a recording of the event (when it’s ready), answers to common questions and links to other blog posts about today’s news on the Mobile blog and Inside Search blog. The Inside Search website is our new one-stop shop for Google search tips, games, features and an under-the-hood look at our technology, so there’s plenty for you to explore.

We’re far from the dream of truly instantaneous access to knowledge, but we’re on our way to help you realize that dream.

Update 4:38p.m.: Watch the video and see a slideshow of today's event below.

Introducing Google Public DNS

When you type into your browser's address bar, you expect nothing less than to be taken to Wikipedia. Chances are you're not giving much thought to the work being done in the background by the Domain Name System, or DNS.

Today, as part of our ongoing effort to make the web faster, we're launching our own public DNS resolver called Google Public DNS, and we invite you to try it out.

Most of us aren't familiar with DNS because it's often handled automatically by our Internet Service Provider (ISP), but it provides an essential function for the web. You could think of it as the switchboard of the Internet, converting easy-to-remember domain names — e.g., — into the unique Internet Protocol (IP) numbers — e.g., — that computers use to communicate with one another.

The average Internet user ends up performing hundreds of DNS lookups each day, and some complex pages require multiple DNS lookups before they start loading. This can slow down the browsing experience. Our research has shown that speed matters to Internet users, so over the past several months our engineers have been working to make improvements to our public DNS resolver to make users' web-surfing experiences faster, safer and more reliable. You can read about the specific technical improvements we've made in our product documentation and get installation instructions from our product website.

If you're web-savvy and comfortable with changing your network settings, check out the Google Code Blog for detailed instructions and more information on how to set up Google Public DNS on your computer or router.

As people begin to use Google Public DNS, we plan to share what we learn with the broader web community and other DNS providers, to improve the browsing experience for Internet users globally. The goal of Google Public DNS is to benefit users worldwide while also helping the tens of thousands of DNS resolvers improve their services, ultimately making the web faster for everyone.

A whole new world to explore

On the Google Earth team, we're big fans of Earth Day, so much so that we couldn't hold out until it arrives next week to release our latest labor of love: Google Earth 4.3. With this version, we have completely rethought how you might interact with the 3D world. We've redesigned the navigation to make it much easier to fly from the heavens down to the streets of your town. And with all of the great user-created buildings in the 3D Warehouse, we wanted to make it easy for you to get right up close to see the rich detail.

Here's a sample of what you'll find in this release:

The road to better path-finding

Way back at the end of 2005, Google Maps' driving directions were on par with other sites, providing basic driving directions in a few seconds. But the nature of the existing system made it nigh impossible to make it faster, add new features, or improve the quality of the routes. And better directions can yield tangible real-world benefits by saving people time and fuel, alleviating frustration, and making travel more pleasant. For all these reasons, it made sense to take a fresh look at the problem and to try to reinvent things such that we could provide a service markedly superior to the status quo.

It's important to us to solve big problems. Automatically finding routes quickly is a hard problem -- especially at a global scale (there are several hundred million road segments worldwide). Even if a routing program is needed to only look at 10% of the map and only examine each segment for a microsecond, it would take tens of seconds to compute a path. Route-finding has to be done automatically because it would be impossibly time-consuming to compute the best routes between all pairs of locations by hand.

Fortunately, we have the tools, technologies, and expertise that make it easier to tackle such hard problems and to build systems for searching large data sets quickly. A small group of engineers (of which I was a part) created the Google Maps route-finding project in Kirkland, WA with the hope of building a world-class system for route-finding. This is the first project I've worked on at Google, and it has given me the opportunity to learn all about the infrastructure we have to build and launch products and features.

We started with the geographic data sets already in use by other groups at Google. Then we designed, built, tested, and deployed a complete route-finding solution in under 12 months. Commutes across the 520 Bridge from Seattle became a favorite test query. As someone with a background in path planning and robotics, it's been great to work on a problem with such substantial theoretical and practical aspects. It took 10 months of hard work, thousands of MapReduce passes, and an uncountable number of lattes to complete.

And 'complete' doesn't really capture it. Our new route-finding system is hundreds of times faster: it can find and describe a cross-continental shortest path in well under a second. Shorter paths can be found proportionately faster.

As evidenced by our 'draggable directions' launch earlier this year, this kind of performance fundamentally changes your Maps experience. It's now possible for you to change your route by simply dragging it or its endpoints. (Here's an example of the above route adjusted to use I-90 instead of WA-520.) No other planning service provides this feature, and it would have been impossible to ship without the massive speedup provided by the system we created.

In the last few months, we've also added other features, like 'avoid highways' and 'estimated time-in-traffic.' Plus, we now cover about 50 countries worldwide. We've raised the bar for what a route-finding system can and should provide. We're pleased with what we've built, and you can expect further improvements in the coming months.

Just recently, the Google Maps route-finding team moved to our new Fremont Engineering office. I'm happy to report we don't have to commute across Lake Washington at all anymore. In fact, nearly half the team cycles in every day! And we're always looking for great people, so if any of this sounds like the kind of challenge you'd be up for, we'd love to hear from you.