Thought Leadership
  • Product design & build

The need for speed: Why brands should prioritise site speed - and how to do it

Tim Dodd
20th May 2019

Google's algorithm now means site speed is as critical as the keywords you rank for. Here's how to avoid getting penalised for a slow site…

  • Google data shows the average mobile site takes 15 seconds to load – but 53% of users will leave if a site takes three or more seconds to load

  • A major algorithm change in 2018 means site speed is now a major ranking factor in mobile search

  • A slow website can cause significant brand damage, and compromise search engine rankings, traffic and ROI from search engine marketing

Before July 2018, if you’d asked any brand what measures they were taking to improve their Google ranking, we’re willing to bet that mobile optimisation, keywords and link quality would have dominated the conversation. Slow site speed was probably pretty low on the list, perceived as a minor technical issue that wasn’t going to win any favours with users but not harm online presence.

This all changed in mid-2018, when Google announced that site speed was now a major ranking factor in mobile search. This algorithm change was the result of a comprehensive Google study that found the average mobile site takes 15 seconds to load – but 53% of users will leave if a site takes three or more seconds to do so. The same study also showed that a one-second delay in load times was linked to 7% fewer conversions.

Google’s message was loud and clear: slow sites would start to slide down the ranks, while lightning-fast sites would enjoy greater visibility, traffic, conversions and revenue. Suddenly, site speed was no longer simply a performance metric – it was matter of success or failure.


Why is speed so important?

More revenue.

While more than half of overall web traffic comes from mobile, conversion rates are significantly lower on mobile. Most mobile sessions are short – around 30 seconds – which can make a slow site feel even more painful. Mobile users expect speed, and speed equals revenue. In 2016, for example, recorded a 7% rise in conversions after reducing load time by 64%.

New customers.

Google is notoriously guarded about the science behind rankings, so the fact it was so forthcoming about site speed says a lot. Getting that front-page position is now going to heavily rely on how fast your site is – and given the first five results receive over 67% of all clicks, being close to the top is critical. Case in point: in 2016, retail site AliExpress said it saw a 27% increase in conversion rates for new customers after reducing load time by 36%.

Better brand perception.

A slow site has a huge impact on how customers view your brand. Short-term, you’ll end up with frustrated users and lost purchases. Long-term, you run the risk of not only alienating your existing customer base, but also deterring new ones. The bottom line: remove all friction that distracts the user from experiencing the value of your product.

Reduced bounce rates.

If a page takes too long to load, visitors grow impatient and go elsewhere. Google then assumes people can’t find what they’re looking for, and will tweak the results to better serve the user. This means that if you’re ranking high for something but seeing a high bounce rate, you’ll be penalised.

How fast should your website load?

After the algorithm announcement, there was one question on everyone’s lips: how fast is fast? According to Google, when it comes to average speed index (or how quickly the mobile page displays content to users) it should take no more than three seconds for a page to load.  

Weight matters too: the total size of a mobile webpage should be no more than 500KB, and the number of individual pieces of content needed to display the entire mobile page should be fewer than 50.

The important thing to remember is that these are all guidelines – site speed has a lot of dependencies and everyone has different expectations of load time.

How do you measure site speed?

Start with Google’s free site speed test. This is the official developer’s tool and it compares your page’s speed to the rest of the web, plus gives you recommendations for improvement.

Then, plug your url into Test My Site. This tool downloads your web page over a simulated 3G mobile connection. Find out your load time on mobile, plus what percentage of your potential traffic will bounce before hitting your landing page.


It’s a good idea to test your site across different tools. Pingdom, GT Metrix and Web Page Test are all free and easy to use. (The latter lets you select the browser, and change the connection speed, too.)

You can also leverage Google’s infrastructure by using its public DNS (this improves security and improves speed) or tap into its open-source JavaScript libraries.

Higher ranking, happier users, more revenue... The decision to speed up your site should be a no-brainer.

How is your digital marketing agency supporting your growth initiatives?

At Mediablaze we use a host of methods to help you with your marketing. To book a masterclass in growth marketing please get in touch with Roger Barr, co-founder and chief digital officer.

Get the latest from Mediablaze

Our emails are packed with digital marketing insight, trends and case studies. On average you will receive one email per month.

Mediablaze on Instagram
Mediablaze on Twitter

30 Panton Street