How important it is to measure the page render/load time in web application

Question

When we test for the Performance of an Web Application what generally people concentrate on ?. Is it the http response time ?. Or is it the time page takes to load/render completely on client browser once after it receives the response from the Server ?.

What is measured generally across the industry ?. Do you have any recommendations in terms which should be done when ?

Do you have any tool recommendations for the same ?.

Can I use the Visual Studio Web Tests to measure the performance in terms of Web page load/render time once after client receives the response. or its just the http response time ?.

Answer 1

In three words : Performance really matters !

My golden rule is pretty simple : You have to measure everything and optimize everything. It's not only a pure tech challenge, but also concerns your business team. Here are some classic exemples from Velocity Conf.

• Bing – A page that was 2 seconds slower resulted in a 4.3% drop in revenue/user.
• Google – A 400 millisecond delay caused a 0.59% drop in searches/user.
• Yahoo! – A 400 milliseconds slowdown resulted in a 5-9% drop in full-page traffic.
• Shopzilla – Speeding up their site by 5 seconds increased the conversion rate 7-12%, doubled the number of sessions from search engine marketing, and cut the number of required servers in half.
• Mozilla – Shaving 2.2 seconds off their landing pages increased download conversions by 15.4%, which they estimate will result in 60 million more Firefox downloads per year.
• Netflix – Adopting a single optimization, gzip compression, resulted in a 13-25% speedup and cut their outbound network traffic by 50%.

What is measured generally across the industry ?. Do you have any recommendations in terms which should be done when ?

From Steve Souders, pioneer in Web Performance Optimization, "80-90% of the end-user response time is spent on the frontend" Start here first : Too many requests, non-optimized images, un-minified content (js/css), do not distribute static throught a cdn are common errros.

On the other hand, do not forget your backend, because this part really depends on load & activity. Some sites are paying the largest amount of performance tax due to backend issues. As the page generation time increases proportionally to the user load, You have to find the throughput peak of your app and check if it's ok with your -own- SLA.

Do you have any tool recommendations for the same ?

There is no magic tool that covers all topics, but many great tools that will help for a specific part of your app.

• Page Rendering : Google Chrome SpeedTracer or IE 11 UI Responsiveness tool
• FrontEnd : PageSpeed, YSlow, WebPageTest.org (online), GtMetrix(online), Pingdom (online)
• Backend : asp.net Mini-Profiler, Glimpse, Visual Studio Profiler & Visual Studio Web/Load Tests
  • Google Analytics for RUM (Real User Monitoring)

Can I use the Visual Studio Web Tests to measure the performance in terms of Web page load/render time once after client receives the response. or its just the http response time ?.

No, Visual Studio Web & Load Test focus only on HTTP request. Javascript is not executed and virtual users are not virtual browsers : it's impossible to measure page laod/redner time. In my company, we use it only for integration tests and load testing.

If you want to read more, you can look at this post (disclamer : I am the author). Another interested link is from Jeff Atwood (co-founder of StackOverflow), Performance is a feature.

Performance is a vast topic, and I only cover here only a small part, but you have a good starting point.