By Colt McAnlis, Google Developer Advocate

The next five billion humans who come online will be doing so from parts of the world where connectivity is costly and slow. With the average website approaching 2 megabytes in size and the average Android game approaching 125 megabytes, users in these markets will have to make a tough choice between content and cost. Compression algorithms, which address this issue, will become critically important over the next decade.

Most developers are content to let compression be someone else’s problem. But the truth is that these algorithms sit in the intersection of optimization, information theory, and pragmatism. These videos will take us through the history of information theory, explain why compression matters, and show how different algorithm families approach this challenge.

Compressor Head, Episode 1 (Variable Length Codes)

Understanding compression algorithms means understanding how humans view and use data. Colt explores the creation of Information Theory, and how it’s spawned the concept of variable length codes, which since the early 1950s have been at the heart of data compression algorithms.

Compressor Head, Episode 2 (The LZ Compression Family)

In the world of compression, one algorithm family reigns supreme. Born in the late 1970s, the Lempel-Ziv algorithms have become the most dominant dictionary encoding schemes in compression. This episode explains why these algorithms are so dominant.

Compressor Head, Episode 3 (Markov Chain Compression)

At the cutting edge of compression algorithms sits the lonely kingdom of Markov Chains. These algorithms adopt an Artificial Intelligence approach to compression by allowing the encoder and decoder to ‘predict’ what data is coming next. In this episode you’ll learn how these magical algorithms compress data, and why some think that they are the future of compression.

While the world of compression is focused on making things smaller, we’re going big with a set of three YouTube videos introducing modern developers to the world of compression algorithms. And they’re all available now, exclusively on our Google Developers YouTube channel at

Colt McAnlis is a games developer advocate who believes every bit counts and that performance matters. He is a Udacity course instructor on HTML5 games and a Book Author. When he's not working with developers, Colt’s been known to compress games, buildings and mountains with his bare hands.

Posted by Louis Gray, Googler

By Matthew Steele and Doantam Phan, PageSpeed Insights Team

/via the Google Webmaster Blog
To help developers and webmasters make their pages mobile-friendly, we recently updated PageSpeed Insights with additional recommendations on mobile usability. 

Poor usability can diminish the benefits of a fast page load. We know the average mobile page takes more than 7 seconds to load, and by using the PageSpeed Insights tool and following its speed recommendations, you can make your page load much faster. But suppose your fast mobile site loads in just 2 seconds instead of 7 seconds. If mobile users still have to spend another 5 seconds once the page loads to pinch-zoom and scroll the screen before they can start reading the text and interacting with the page, then that site isn’t really fast to use after all. PageSpeed Insights’ new User Experience rules can help you find and fix these usability issues. 

These new recommendations currently cover the following areas: 
  • Configure the viewport: Without a meta-viewport tag, modern mobile browsers will assume your page is not mobile-friendly, and will fall back to a desktop viewport and possibly apply font-boosting, interfering with your intended page layout. Configuring the viewport to width=device-width should be your first step in mobilizing your site.
  • Size content to the viewport: Users expect mobile sites to scroll vertically, not horizontally. Once you’ve configured your viewport, make sure your page content fits the width of that viewport, keeping in mind that not all mobile devices are the same width.
  • Use legible font sizes: If users have to zoom in just to be able read your article text on their smartphone screen, then your site isn’t mobile-friendly. PageSpeed Insights checks that your site’s text is large enough for most users to read comfortably.
  • Size tap targets appropriately: Nothing’s more frustrating than trying to tap a button or link on a phone or tablet touchscreen, and accidentally hitting the wrong one because your finger pad is much bigger than a desktop mouse cursor. Make sure that your mobile site’s touchscreen tap targets are large enough to press easily.
  • Avoid plugins: Most smartphones don’t support Flash or other browser plugins, so make sure your mobile site doesn't rely on plugins.
These rules are described in more detail in our help pages. When you’re ready, you can test your pages and the improvements you make using the PageSpeed Insights tool. We’ve also updated PageSpeed Insights to use a mobile friendly design, and we’ve translated our documents into additional languages.

As always, if you have any questions or feedback, please post in our discussion group

Posted by Louis Gray, Googler

By Katie Miller, Google Developer Marketing

From making your apps as powerful as they can be to putting them in front of hundreds of millions of users, our focus at Google is to help you design, develop and distribute compelling experiences for your users. At Google I/O 2014, happening June 25-26 at Moscone West in San Francisco, we’re bringing you sessions and experiences ranging from design principles and techniques to the latest developer tools and implementations to developer-minded products and strategies to help distribute your app.

If you're coming in person, the schedule will give you more time to interact in the Sandbox, where partners will be on hand to demo apps built on the best of Google and open source, and where you can interact with Googlers 1:1 and in small groups. Don’t worry, though--we’ll have plenty of content online for those following along remotely! Visit the schedule on the Google I/O website (and check back often for updates). As you start your I/O planning, we want to highlight the experiences we’re working on to help you build and grow your apps:

  • Breakout sessions: This year, we’ll once again bring you a deep selection of technical content, including sessions such as "What's New in Android"and "Wearable computing with Google” from Android, Chrome and Cloud, and cross-product, cross-platform implementations. There will be a full slate of design sessions that will bring to life Google’s design principles and teach best practices, and an update on how our monetization, measurement and payment products are better suited than ever to help developers grow the reach of their applications. Sessions from Ray Kurzweil, Ignite and Women Techmakers will take the stage and make us uncomfortably excited about what is possible. The first sessions are now listed, keep checking back for more.
  • Workshops and code labs: Roll up your sleeves, dig in to hands-on experiences and code. Learn how to build better products, apply quantitative data to user experiences, and prototype new Glassware through interactive workshops on UX, experience mapping and design principles. To maximize your learning and give you more interaction with Googlers and peers, visit our coding work space, with work stations preloaded with self-paced modules. Dive into Android, Chrome, Cloud and APIs with experts on hand for guidance.
  • Connect with Googlers in the sandbox: Check out your favorite Google products and meet the Googlers who built them. From there, join a ‘Box talk or app review, ranging from conceptual prototyping, to performance testing with the latest tools, to turning your app into a successful business.
  • Learn from peers at the partner sandbox: We love to see partners build cool things with Google, and have invited a few of them to showcase inspiring integrations of what’s possible. You will be able to see demos and talk in-depth with them about how they designed, created and grew their apps.
  • Beyond Moscone, with I/O Extended: Experience I/O around the world, in an event setting, with I/O Extended. The I/O Extended events include everything from live streaming sessions from I/O to local speaker sessions and hackathons. It is great to see so many events taking place around the world, and we can't wait to see I/O Extended events have another strong year.

We look forward to seeing you next month, whether it’s in-person in San Francisco, at I/O Extended or online through the livestream!

Katherine Miller is part of the Developer Marketing team, working on session programming for Google I/O and developer research efforts. In her spare time she runs (both competitively and after her 2 children) and memorizes passages from beloved children's books.

Posted by Louis Gray, Googler