Step1 : Open Firefox browser on your machine.
Step 2: Click on the Menu (Top right)
Step 3: Click on Add-ons from the menu tab
Step 4: Search for Firebug in the search section (Top right)
Step 5: Look for Firebug in the search results and click install.
Step 1: Enter the URL of the website you want to debug in the FireFox browser.
Step 2: Click on the firebug icon while the site is still loading.
Step 3: A Firebug window will open.Select Net from the Menu on the top.
(Enable Net if its the first time)
Step 5: Under the section All, you can find the Timeline details of the respective website.