Chrome has a built in tool to measure how many seconds a webpage loads

  • Open Chrome
  • Press F12 on your keyboard
  • Click Network and disable cache and then click the circle to disable traffic recording

  • Get the website you want to time ready in the address bar and then when you press enter click the circle button to start recording and when the page finishes loaded stop the recording
    • You can also go to the webpage then press f5 to reload the page after starting recording

You can then see how long each segment of your page took and at the very bottom it tells you the full time after Finish:

Reference: https://www.syskit.com/blog/sharepoint-page-performance-why-does-it-matter/