Research indicates that 80% of the end-users response time is spent on the front-end, remaining 20% includes all of database & other back-end activities such as web-services.
There are numerous factors that contribute towards the end-users response time on the front-end:
- # of HTTP Requests
- Whether or not if the site is using CDN (Content Delivery Networks)
- Placement of Stylesheets in the HTML
- CSS expressions usage in the code
- Are your JS and CSS internal to HTML or external
- Duplicate scripts
- Are your AJAX cachable?
- # of DOM elements
- Are you using iFrames?
- Do you have lot of 404s (Page not found errors) on your site?
- Cookie size
- Image size & optimization
- CSS Sprites
- Missing image size (height and width) in the code
- Size of HTML
We will discuss possibly each of the above in sufficient details in up-coming posts with examples, tools, suggestions, tips, techniques, and tricks to boost page performance.