What is TTFB?
Time to First Byte (TTFB) is the time it takes a user to receive the first byte from a web server when requesting a particular URL. After testing several websites, data showed that although there is no solid evidence to suggest ranking had a strong correlation to TTFB values, the correlation was strong enough to analyse further. From graphical data captured by search results, it is evident that websites with a lower TTFB ranked higher than those with higher TTFB. And this isn’t just valid for short keyword searches, it is also valid for long ones with multiple keywords.
The Effect of Website Speed on Search Ranking
Google search uses a large number of parameters to determine search ranking. These factors are mostly linked to the content on the web page, its URL, headers and titles, the authenticity of the web page itself – domain age and name, quality of inbound links, and number of inbound links. In 2010, Google announced that website speed would start factoring into search rankings, meaning the speed at which a user could view the content of a web page would determine its ranking in search engine results.
However, the exact definition of website speed remained ambiguous and led to much speculation.
It was evident that Google had decided to act upon something that was clearly visible to all users of their search engine – the speed at which a web page loaded – which in turn determines how smooth a user’s experience is. Therefore, sites with poor user experiences were penalized in the search results.
When investigations to determine the basis on which pages ranked high or low on the basis of website speed, the only measure found to offer significant correlation was Time to First Byte (TTFB).
How to measure TTFB
The most common tool for measuring a website’s performance is Web Page Test, a diagnostic tool initially developed by America Online. Web Page Test is under active development by GitHub, a web based hosting service for open source projects.
Web Page Test is an easy to use tool to understand where your web page stands in terms of performance. Visit their webpage and select a location most suitable to the user and run a test against the web page. Web Page Test will return a ‘waterfall’ chart with details of the website’s performance, including TTFB. If the TTFB of a web page is found to be too long (slow), then the next step is to determine the cause of and address the problem. One main cause of high TTFB values is Latency.
Latency is the time taken to transmit a single data packet from one location to another. Contrary to what most people believe, having a high bandwidth internet connection does not guarantee low latencies. This is because latency measures how far a packet of data has to travel, regardless of the bandwidth of a user. A data packet will have to travel the same distance to a certain server, whether it travels over a high bandwidth connection or a low bandwidth one.
How much latency must a web page have to be ranked well?
From research conducted on the correlation between TTFB and page ranking, the top ranking websites had a TTFB of 350 millisecond. The Ideal TTFB value was found to be in the vicinity of 500 ms or less. Of this value, 100 ms should be round trip latency (time taken for the data packet to travel to the server and back), and the remaining 400ms should be spent on backend processing.
How to improve latency using a Content Delivery Network (CDN)
Since latency is the time taken for a data packet to travel a certain distance, the solution is to reduce the distance between the two locations. An ideal way to achieve this is by moving static content on your web page to a Content Delivery Network (CDN), which replicates this content to multiple locations around the world, so that your users can access the content more easily. If you have any doubts regarding CDN, or anything related to SEO, you can contact an SEO company for help and guidance on improving your website speed.