SEO Questions: What factors into website speed?
Page speed is now a (small) factor in the mobile-first index, and therefore impacts SEO. It affects organic performance, and more importantly, user experience. Many people don’t consider speed since many websites are already in-line with modern standards. That said, it is regarded as one of the top ten SEO ranking factors.
Speed is essential, not just for SEO, but also for UX. If a website takes, say, more than three seconds to load, then most users will simply leave.
There are many aspects that you can take to improving page speed, so let’s take a look.
Time to First Byte
Time to First Byte, or TTFB, is one of the most important speed signals for Google and users. Additionally, TTFB affects organic performance, as a slow-loading website is taking time away from Google crawling other websites too; something which does not bode well for slow-loading sites.
HTTP/2 is the next version from the widely used HTTP/1.1. The technology utilises multiplexing, meaning that a webpage’s resources load simultaneously rather than consecutively. This is applicable for every website, and massively helps websites that use a lot of separate resources (e.g. lots of images on a webpage), ultimately cutting total load time.
We’ve seen websites cut their total load time by more than 40% with this technology. Considering how easy it is to implement, and how fast it can “make” your website, there’s no point not implementing the new technology.
A website can deploy HTTP/2 off-the-shelf with the use of an advanced CDN such as Cloudflare, but even without, it is relatively easy to implement on most web servers.
People typically ask questions like “does Cloudflare speed up my website?”
Content delivery networks (CDNs) are servers that you can leverage your website onto. CDNs help speed by storing static assets on their many global servers. The CDN will determine the location of the user and direct it to the closest edge server it can find.
Such networks are freely available, and there are many different options covering speed and security, among others. There is also a wide range of brands to choose from, from AWS to Alibaba.
We recommend using Cloudflare, however, as we have developed our SEO Sloth for, which allows you to carry out A/B testing and much more for free (still in closed sign-ups).
Image compression + formats
Many websites now use visuals to help deliver content to users to provide a better UX and help make their website more captivating. However, with more visuals usually comes more images – especially large images – and this can result in your webpages having a very high load time because of this.
Most CMSs do provide a tool to do this automatically, meaning you don’t have to worry about doing anything yourself. Some more advanced tools convert these images to more advanced formats like WebP, which utilise greater compression technologies – meaning smaller file sizes.
Content Compression Technologies
Static files, like CSS and JS, can be compressed by your server software before being transferred over the internet using technologies GZIP or Google’s Brotli.
Files under this compression (assuming they are also minified – the process of removing unnecessary line breaks from the code) can reduce file size up to 90%, helping reduce total load time.
These only apply to files like CSS, JS, HTML, SVG, etc. and unfortunately do not touch images.
Browsers must establish a relationship between the IP by performing DNS lookups before starting to transfer files. This means that for every domain you use (e.g. google.com, googleapis.com), it adds more time to the total load time.
To combat this, you can try to reduce the number of hosts used or use a DNS prefetch rule in your website’s <head> to pre-emptively establish a connection; helping to reduce load time.
Your browser will make several requests to different servers – one request for each file loaded for each time a new webpage is loaded.
Having many of these (possibly over 100) can affect the crawlability of your website. Of course, if your page has a lot of content and uses a lot of external elements reasonably, then it is acceptable. However, if it is a site-wide situation, then search engines might not render all requests, which can affect the value of the page.
Reviewing the requests on the top landing page, for starters, can be used to counter this issue. There may be some redundant requests made by the browser, or there could JS or CSS files which can be combined.
User Journey Speed
Speed, as mentioned above, can massively affect UX without even touching SEO. This, however, only happens in certain circumstances where Google cannot send requests with its user-agents, but human users can.
For example, a user may want to compare to houses on a house comparison website. To Googlebot, the entire page has loaded, and everything is fine, however to the user, the API still must return the results, which in some cases can take over a minute. Something in this period can severely increase the exit rate and decrease conversions on the website.
Additionally, a user may want to book a hotel but must wait for the API to return the necessary data for them about booking information etc. There can sometimes be a chance that the API will take a long time to load – perhaps around 30 seconds. Due to impatience, explicitly developed from the internet, users will most likely get frustrated and exit the page.
Ultimately, although your organic performance won’t be affected by slow APIs, your conversion rate will.
Post publish edit: Web vitals is also now a critical part of the site page speed measurements. Please read our new Introducing Web Vitals: A guide to using and visualising their data article.
If you want help with speeding up your website, contact us at [email protected] or call us on 01134605671.