Why does webpage speed matter?

When a customer goes to a restaurant, slow waiter service often leads to bad reviews and fewer customers in the future. Likewise, slow site speed can lead to poor search engine rankings, lower overall site traffic, and negative user experience.

Site speed, or site performance, is about how quickly a browser loads a fully-functional page of a given website. Poorly performing sites with slow content display in the browser can drive users away. Vice versa, quick loading sites tend to get more traffic and have better conversion rates.

In web jargon, a user is converted when he or she takes an action the web page developers want him or her to take. For example, a user is converted when he decides to buy an item and clicks the "buy" button. However, the user does not have to buy something to 'get converted', as the web page may have different purposes.

Other examples of user conversions include filling out and submitting a contact form, answering a questionnaire, or even just going to the next page of the site. The conversion rate is a percentage of the total number of visitors to a web page to the ones who made a conversion. If 100 users visited a page promoting baby strollers, and 2 users clicked on the “buy” button, the conversion rate is 2%.

Conversion Rate Optimization (CRO) is the practice of increasing conversion rate to the highest possible level. Conversion rate optimization is an ongoing process. If a page's conversion rate is not 100% (that is by the way highly unlikely), it can always be optimized. Numerous studies have shown that site speed affects conversion rate (or the rate at which a user takes the desired action). Not only do more users stay on fast-loading sites, but they also convert more compared to slow-loading sites.

Several companies have found that reducing page load time by a few milliseconds increases conversion rates. As a result, improved site performance means increased user conversion and therefore increased revenue for the site owner.

The bounce rate is the percentage of users who leave the site after viewing only one page. Users are more likely to close the window or leave if a page doesn't load within a few seconds.

Because Google tends to prioritize relevant information to users as quickly as possible, site performance is an important factor in Google's search rankings.

Site performance on mobile devices is also especially important for SEO.

Long page loading time and poor response time to user actions cause inconveniences for a page visitor. Waiting for content to get loaded frustrates users, leading them to abandon the site or app altogether. 47% of customers expect a webpage to load within 3 seconds or less. The conversion rate can fall by up to 20% for each second delay while loading a mobile page