{"id":10870,"date":"2018-09-20T01:59:34","date_gmt":"2018-09-20T01:59:34","guid":{"rendered":"https:\/\/www.siteground.com\/blog\/?p=10870"},"modified":"2025-08-05T13:42:47","modified_gmt":"2025-08-05T13:42:47","slug":"understanding-ttfb","status":"publish","type":"post","link":"https:\/\/academy.siteground.com\/en\/understanding-ttfb\/","title":{"rendered":"Understanding Site Speed: The Time to First Byte (TTFB)"},"content":{"rendered":"\n

When troubleshooting a slow website, there are a few helpful metrics to determine the causes and solutions. One of those metrics is the Time To First Byte (TTFB), a measurement used by all site performance benchmarking tools. It\u2019s an important metric to measure how fast your website starts loading in a specific location or with a particular combination of settings. Understanding TTFB can help you get a better grasp of how website speed works, what\u2019s slowing down your site, and how to fix it.<\/p>\n\n\n\n

<\/span>What is Time To First Byte (TTFB)?<\/span><\/h2>\n\n\n\n

TTFB measures the time elapsed between the moment a web user makes an HTTP request, like loading a webpage, to the time the first byte is received by the client’s browser<\/strong>. Many use this reading as a rudimentary way to test server speed and while this works, it\u2019s only half the story. If the website you\u2019re trying to load uses a Content Management System (CMS)<\/a> like WordPress, the server must do all the CMS computations required to produce content. The PHP service must load your MySQL database, get the content, calculate the appropriate HTML output, and return it to the website visitor.<\/p>\n\n\n\n

If you have a slow CMS, all those steps can take time and you may receive bad TTFB results like 1-3 seconds or more. That doesn\u2019t necessarily mean your hosting server is slow or experiencing issues. More often than not, it means you have too many plugins or extensions, you\u2019re not using a caching system, or you\u2019re using an old PHP version. Of course, it is a totally different story if you are measuring a static HTML page with a slow TTFB. Then, you may want to start your investigation from the server itself, as there are no other factors impacting the performance of your site.<\/p>\n\n\n\n

<\/span>How Does Dynamic Caching Affect TTFB?<\/span><\/h2>\n\n\n\n

Dynamic Caching is like having your local barista remember your order instead of having to repeat it every time. Because they already know your drink, they can start making it as soon as you walk in, serving it to you that much faster. Caching works in a similar way by storing the data required to serve a webpage for the next time.<\/p>\n\n\n\n

Our Dynamic Caching<\/a> uses NGINX as a reverse proxy. This means that all the computing from your PHP and MySQL services is stored in the server\u2019s RAM. When a visitor gets a cached response from us, it\u2019s like they\u2019re loading a static HTML page \u2014 only faster! It\u2019s faster because the content is served from memory and not from the server\u2019s hard drive. Although SSDs are super fast, nothing compares to the server RAM when it comes to speed.<\/p>\n\n\n\n

If you have the Dynamic Caching on and still have slow TTFB, there are two things to check:<\/p>\n\n\n\n