The amount of time it takes users to complete multiple tasks on your site is affected by the front-end performance. How fast can they click on a button while reading through your product page? How quickly does the search results page take to load? According to Google, if a search results page takes more than half a second to load, it can decrease traffic and your ad revenue. Users expect web pages to load as fast as possible.
Knowing what your customers expect is one part of the equation. The other part is to know if you can cope or not. Designing sites with multiple rich content and lots of dynamic elements means it might be difficult to keep up.
Design for Performance
At the basic level, the performance of a website can be traced to the design. Everything related to performance weighs heavily on the choices made at design. It impacts the load speed and the conversion rate of your site. Every little detail needs to be questioned. What value does the wide background add? Is it causing more havoc than it is helping your site? Sometimes, you might have to do as little as bundling your images into a sprite. This could increase the total homepage size while decreasing the number of requests made. This will lead to a reduction in the entire homepage load time.
Coding for Performance
After designing, coding is another area that affects front-end performance. Sometimes, this could be fixed by cleaning your HTML, and everything else will follow suit. The toughest tasks here will be renaming non-semantic elements in the HTML. Theming concerning semantics like "article" and less with design, you will start reaping the rewards for your efforts. Some of these elements end up in our code due to the need to have more weight in CSS selectors. The right way to go will be to clean up our CSS while adding more specificity but we end up adding IDs that are unnecessary and other elements to our HTML.
Once you're done with theming semantics together, you should clean up your CSS to eliminate inefficient selectors.Inefficient selectors have a way of increasing page load time, and they are harder to re-design or customize. Efficient CSS selectors are easier to redesign making them quicker to customize the design and styles in the future. Good code is easier to edit, and an editable code leads to good front-end performance.
The third stage is purging your HTML of div-itis. The goal here is to ensure your markup ends up cleaner so the CSS will become smaller and easier to redesign and edit. That way, you end up saving lots of development time and page load time.
Finally, work on creating repurposable code which will also save you time and results when loading your CSS and HTML files. This makes it easier to maintain and redesign your files later and keep them in smaller page sizes.
You have to optimize requests so your site will request for fewer ones. Requests occur when the site has to fetch a file or a record. The cleaner the markup, the more infrequent requests the browser has to make, and the less time the user will spend waiting for the browsers to send that information back.
For most sites, responsive design means more images and CSS files loading, which increases the weight of the requests. You can still get faster load times when the number of requests has been optimized, so only important details are loaded.
The first step here is to focus on creating sprites - this ensures you save as many image requests as you can. Creating sprites can reduce the page load time by as much as 10%. After creating sprites, clean up the images by creating one sprite for repeating backgrounds. For no-repeat backgrounds, you can create one transparent sprite for this, inclusive of your logo and icons. At this stage, you will need a tool that will figure out how best to serve your images to your users. After regenerating the images, optimize them by making them smaller with a tool like ImageMagick, TinyPNG and etc.
Measuring Front-End Performance
What is not measured cannot be changed. You have to determine whether your efforts are paying off. This will include using Google's PageSpeed or YSlow by Yahoo!. These tools will also give you more suggestions on how to improve your page load time, elements blocking faster page rendering and how to optimize the social scripts on your page.
Front-end performance will always affect your users, and it is your job to understand how it works, measure it and improve it for a better page load time. A faster front-end performance will lead to better conversion rates for your business, and it will ensure your site accomplish all that it wants to in a short amount of time.