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Responsive Responsive Design

Now more than ever, we’re designing work meant to be viewed along a gradient of different experiences. Responsive web design offers us a way forward, finally allowing us to “design for the ebb and flow of things.”

With those two sentences, Ethan closed the article that introduced the web to responsive design. Since then, responsive design has taken the web by storm. Seemingly every day, some company is touting their new responsive redesign. Large brands such as Microsoft, Time and Disney are getting in on the action, blowing away the once common criticism that responsive design was a technique only fit for small blogs.

Certainly, this is a good thing. As Ethan and John Allsopp before him, were right to point out, the inherent flexibility of the web is a feature, not a bug. The web’s unique ability to be consumed and interacted with on any number of devices, with any number of input methods is something to be embraced.

But there’s one part of the web’s inherent flexibility that seems to be increasingly overlooked: the ability for the web to be interacted with on any number of networks, with a gradient of bandwidth constraints and latency costs, on devices with varying degrees of hardware power.

A few months back, Stephanie Rieger tweeted

“Shoot me now…responsive design has seemingly become confused with an opportunity to reduce performance rather than improve it.”

I would love to disagree, but unfortunately the evidence is damning. Consider the size and number of requests for four highly touted responsive sites that were launched this year:

  • 74 requests, 1,511kb
  • 114 requests, 1,200kb
  • 99 requests, 1,298kb
  • 105 requests, 5,942kb

And those numbers were for the small screen versions of each site!

These sites were praised for their visual design and responsive nature, and rightfully so. They’re very easy on the eyes and a lot of thought went into their appearance. But the numbers above tell an inconvenient truth: for all the time spent ensuring the visual design was airtight, seemingly very little (if any) attention was given to their performance.

It would be one thing if these were the exceptions, but unfortunately they’re not. Guy Podjarny, who has done a lot of research around responsive performance, discovered that 86% of the responsive sites he tested were either the same size or larger on the small screen as they were on the desktop.

The reality is that high performance should be a requirement on any web project, not an afterthought. Poor performance has been tied to a decrease in revenue, traffic, conversions, and overall user satisfaction. Case study after case study shows that improving performance, even marginally, will impact the bottom line. The situation is no different on mobile where 71% of people say they expect sites to load as quickly or faster on their phone when compared to the desktop.

The bottom line: performance is a fundamental component of the user experience.

So, given it’s extreme importance in the success of any web project, why is it that we’re seeing so many bloated responsive sites?

First, I adamantly disagree with the belief that poor performance is inherent to responsive design. That’s not a rule – it’s a cop-out. It’s an example of blaming the technique when we should be blaming the implementation. This argument also falls flat because it ignores the fact that the trend of fat sites is increasing on the web in general. While some responsive sites are the worst offenders, it’s hardly an issue resigned to one technique.

To fix the issue, we need to stop making excuses and start making improvements instead. Here, then, are some things we can do to start improving the state of responsive performance, and performance in general, right now.

Create a culture of performance

If you understand just how important performance is to the success of a project, the natural next step is to start creating a culture where high performance is a key consideration.

One of the things you can do is set a baseline. Determine the maximum size and number of requests you are going to allow, and don’t let a page go live if either of those numbers is exceeded. The BBC does this with its responsive mobile site.

A variation of that, which Steve Souders discussed in a recent podcast is to create a performance budget based on those numbers. Once you have that baseline set, if someone comes along and wants to add a something to the page, they have to make sure the page remains under budget. If it exceeds the budget, you have three options:

  1. Optimize an existing feature or asset on the page
  2. Remove an existing feature or asset from the page
  3. Don’t add the new feature or asset

The idea here is that you make performance part of the process instead of something that may or may not get tacked on at the end.

Embrace the pain

This troubling trend of web bloat can be blamed in part on the lack of pain associated with poor performance. Most of us work on high-speed connections with low latency. When we fire up a 4Mb site, it doesn’t feel so bad.

When I tested the previously mentioned 5,942kb site on a 3G network, it took over 93 seconds to load. A minute and a half just staring at a white screen. Had anyone working on that project experienced that, you can bet the site wouldn’t have launched in that state.

Don’t just crunch numbers. Fire up your site on a slower network and see what it feels like to wait. If you don’t have access to a slow network, simulate one using a tool like Slowy, Throttle or the Network Conditioner found in Mac OS X 10.7.

Watch for low-hanging fruit

There are a bunch of general performance improvements that apply to any site (responsive or not) but often aren’t made. A great starting point is to refer to Yahoo!‘s list of rules.

Some of this might sound complicated or intimidating, but it doesn’t have to be. You can grab an .htaccess file from HTML 5 Boilerplate or use Sergey Chernyshev’s drop-in .htaccess file. You can use tools like SpriteMe to simplify the creation of sprites, and ImageOptim to compress images.

Just by implementing these simple optimizations you will achieve a noticeable improvement in terms of weight and page load time.

Be careful with images

The most common offender for poor responsive performance is downloading unnecessarily large images, or worse yet, multiple sizes of the same image.

For background images, simply being careful with where and how you include the image can ensure you don’t get caught in the trap of multiple background images being downloaded without being used. Don’t count on display:none to help. While it may hide elements from displaying on screen, those images will still be requested and downloaded.

Content images can be a little trickier. Whatever you do, don’t serve a large image that works on a large screen display to small screens. It’s wasteful, not only in terms of adding weight to the page, but also in wasting precious memory. Instead, use a tool like Adaptive Images or to make sure only appropriately sized images are being downloaded.

The new <picture> element that has been so often discussed is another excellent solution if you’re feeling particularly future-oriented. A picture polyfill exists so that you can start using the element now without any worries about support.

Conditional loading

Don’t load any more than you absolutely need to. If a script isn’t needed at certain sizes, use the matchMedia polyfill to ensure it only loads when needed. Use eCSSential to do the same for unnecessary CSS files.

Last year on 24 ways, Jeremy Keith wrote an article about conditional loading of content in a responsive design based on the screen width. The technique was later refined by the Filament Group into what they dubbed the Ajax-Include Pattern. It’s a powerful and simple way to lighten the load on small screens as well as reduce clutter.

Go vanilla?

If you take a look at the HTTP Archive you’ll see that other than image size, JavaScript is the heaviest asset on a page weighing in at 215kb on average. It also boasts the fifth highest correlation to load time as well as the second highest correlation to render time.

Much of the weight can be attributed to our industry’s increasing reliance on frameworks. This is especially a concern on mobile devices. PPK recently exclaimed that current JavaScript libraries are just “too heavy for mobile”. “Research from Stoyan Stefanov on parse times supports this. On some Android and iOS devices, it can take as long as 200-300ms just to parse jQuery.

There’s nothing wrong about using a framework, but the problem is that they’ve become the default. Before dropping another framework or plugin into a page, we should stop to consider the value it adds and whether we could accomplish what we need to do using a combination of vanilla JavaScript and CSS instead. (This is a great example of a scenario where a performance budget could help.)

Start thinking beyond visual aesthetics

We love to tout the web’s universality when discussing the need for responsive design. But that universality is not limited simply to screen size. Networks and hardware capabilities must factor in as well.

The web is an incredibly dynamic and interactive medium, and designing for it demands that we consider more than just visual aesthetics. Let’s not forget to give those other qualities the attention they deserve.

About the author

Tim Kadlec is a developer living in a tiny town in the north woods of Wisconsin. He’s very passionate about the Web and can frequently be found speaking about what he’s learned at a variety of web conferences.

Tim is the author of Implementing Responsive Design: Building sites for an anywhere, everywhere web (New Riders, 2012) and was a contributing author for the Web Performance Daybook Volume 2 (O’Reilly, 2012). He writes sporadically at and you can find him sharing his thoughts in a briefer format on Twitter at @tkadlec.

More articles by Tim