Time To First Byte
From a hosting perspective, Time to first byte (TTFB) is the relevant metric to look for when testing the performance of a Magento store. TTFB refers to the time between a customer entering your store URL into their browser and the first byte of data being received back from the server. During this time a customer's browser will not provide any visual indication of content being loaded. A long TTFB can often be attributed to poorly written code - this can lead to a store ‘crashing’ during busy times such as sale events.Popular Speed Test Tools
- GTmetrix
GTmetrix’s results can cause some confusion due to the weighting of its letter grade system. When performing a speed test using GTmetrix, consider the geographical location of the test server as this can impact the accuracy of results. The Waterfall breakdown is a good place to see TTFB. - Pingdom Speed Tester
Using the Pingdom Speed Tester, TTFB can be found under the File Load section of the test results. This provides a waterfall breakdown of time taken to load each file individually. The TTFB is represented in the waterfall breakdown as wait time. - Google PageSpeed
Google PageSpeed suggests possible fixes for a poorly performing website, however the information is more focused on static page content. The TTFB value is listed as server response time. - WebPageTest
WebPageTest provides a waterfall breakdown, with TTFB on the first and consecutive loads to account for caching.
Definition of a fast site
A fast Magento site is one in which the page load times of the Homepage, Product and Category pages are all within a reasonable range. Listed below are the speed values expected on a Magento store hosted with M.D.G. IT.M.D.G. IT VPS Hosting Packages:
- Homepage - 120ms - 450ms
- Product - 120ms - 450ms
- Category - 120ms - 450ms
- Homepage - 300ms - 800ms
- Product - 600ms - 950ms
- Category - 600ms - 950ms
