The number of users who say that their primary device for accessing the Internet is a smartphone, tablet, or some other smart/mobile device is growing furiously every year. As such, you should pay careful attention to how your site works for those who are on the go. Performance is one of the biggest predictors in website success, so you need to ensure that your mobile offerings are in tip-top shape to maintain a competitive advantage in an already-crowded marketplace.

What does mobile performance include?

You could ask twenty people what falls under the umbrella of mobile performance and get twenty different responses, but we will summarize it as follows: mobile performance includes anything that impacts the user when they are trying to accomplish a task with a mobile device. While this is a vague definition, we want to keep it this way so that you consider the specifics applicable to your situation.

It’s important to know where your users are starting from and what their end goal is; without this information, you can’t even begin to offer them what they want. You also need to consider all the factors that impact your user’s experience. Does your mobile site load quickly even when there is a larger than usual amount of traffic? Can users checkout without your shopping cart crashing? Can someone navigate between pages without having to frequently re-authenticate?

There are a myriad of factors that affect mobile performance, including your code, your host/server configuration, the device itself, the network used by the device, and so on. Notice that not all these aspects are under your direct control, which adds another layer of complexity.

Why is mobile performance important?

In 2015, Dimensional Research’s mobile app user survey found that almost all users (96%) say mobile performance is important, with 75% of those respondents saying it is very or critically important.

Unfortunately, the same survey also determined that mobile apps, in general, fail to meet user expectations. This is problematic since 55% of respondents said they hold the app responsible for performance issues (regardless of the actual cause) and 37% indicate that performance issues cause them to think negatively of the brand.

Furthermore, mobile users tend to be more engaged, spend more, and shop more often. However, you have few chances to tap into this pool of users–if your product doesn’t meet their expectations, you’ll likely lose their business. 79% of users indicated that if they’re unsatisfied with a site, they’re less likely to return.

These are lost leads, and in a crowded marketplace, conversions are of the utmost importance when you’re trying to gain an advantage over your competitors. If this is discouraging, remember on the flip side that sites that work well can boost conversions.

How performant should my site be?

About half of the respondents to Dimensional Research’s mobile user survey say they expect a response to their requested action in two seconds or less, and Kissmetrics finds that half of consumers expect a shopping page to load in the same amount of time (Akamai has found that some 20% of users expect actions to be completed instantaneously). However, increase that number to four or more seconds, and you’ll have lost 91% of your users.

At one point historically, the rule-of-thumb was users would allow 3 seconds to elapse before navigating elsewhere, but today developers of mobile products should strive to be closer to 2 seconds or fewer.

How do I improve the performance of my mobile product?

Mobile devices tend to run on networks slower than those used by desktops or laptops, so your goal should be to ensure that your site requires as few resources to run as possible, is served up by a speedy host, and is designed to display properly on smaller screens.

This section provides specifics on how to achieve these goals.

Cache Resources

Caching is the storage of resources on a user’s device so these resources can be accessed without being downloaded again. Caching means that your user sees the resource (whether it’s a page, image, or set of text) sooner than if they were uncached. Furthermore, if the cached resources are render-blocking there’s less time spent by the browser waiting for other required files to download before it can parse the required assets.

Compress and Resize Images

Images can make or break a site, but these files tend to be large. To make them smaller, make sure you use the correct image format and compress the image as much as possible. These fixes are relatively simple, but can result in huge resource savings when multiplied by the many images you probably display on your site, the savings in resource usage can potentially be huge.

Reduce HTTP Requests

Fewer calls to the server mean fewer requests for which the browser has to wait to receive and parse. With a fast enough network, this might not be a concern, but given that most mobile devices operate on slower networks, a large number of HTTP requests contributes greatly to slow page load times.

To reduce HTTP requests, consider consolidating files (such as JavaScript and CSS), reusing files across multiple HTML pages, and, in cases of small JavaScript/CSS snippets, embedding your code/markup into your HTML. Doing so may result in larger files, but in a situation where both incoming and outgoing calls are slow, your site will probably load faster when requesting one larger file instead of multiple smaller files.

Use Load Validations

Even if your site hasn’t fully loaded, you can “trick” your users’ minds, so to speak, by displaying validation that indicates that your site is loading. Perception matters and people perceive load times as 15% slower than they actually are. Whether you use a status bar with the percentage loaded displayed or simply rely on visual cursor changes, make sure your users know that something is happening in the background, even if they can’t see it.

Test Early and Often

Don’t wait until you’re ready to ship to test for performance! When you make performance a part of your software development life cycle, you can get ahead of any performance defects when changes to your product are less expensive to implement.

Automate Monitoring and Optimization

Not only can you automate gathering data on how your site is performing, but you can also automate testing based on that data. Even if you don’t have a dedicated performance engineering team whose job is to maintain optimal performance for your site, you can obtain some of these benefits using Rigor Optimization, which checks your site against hundreds of custom rules and notifies you if there are defects that you should fix.


One of the key factors that determine the success of mobile sites is performance, so if yours isn’t in the best shape, now is the time to fix that. Consumers find slow load times and site crashes unacceptable, and if your product doesn’t perform the way your customers expect it to, they’ll simply not do business with you (best case scenario) or take their business to your competitor (worst case scenario).

Monitoring your mobile site and optimizing it, however, doesn’t need to be a tedious process. Rigor Monitoring and Optimization can help you with both. Not only does Rigor tell you what defects need to be fixed, but it also provides step-by-step instructions on how to take action. These improvements are organized by severity and difficulty so you know how to allocate resources to garner the biggest wins.

Contact Rigor today to see how we can help you give you insight into your customers’ mobile experience, so you can maximize your performance efforts.