The performance of a website is definitely one of the most important factors that affects its user experience. Not only that, but the performance can also affect sales and search engines ranking. Please take a look at some key facts below:
About Response Times
Jakob Nielsen says that there are 3 important limits in applications response time:
- 0.1 second is about the limit for having the user feel that the system is reacting instantaneously, meaning that no special feedback is necessary except to display the result.
- 1 second is about the limit for the user’s flow of thought to stay uninterrupted, even though the user will notice the delay. Normally, no special feedback is necessary during delays of more than 0.1 but less than 1.0 second, but the user does lose the feeling of operating directly on the data.
- 10 seconds is about the limit for keeping the user’s attention focused on the dialogue. For longer delays, users will want to perform other tasks while waiting for the computer to finish, so they should be given feedback indicating when the computer expects to be done. Feedback during the delay is especially important if the response time is likely to be highly variable, since users will then not know what to expect.
I suggest to take this into consideration when you will develop your application and I also want to highlight the fact that these limits do not apply only to the page load only. They are also applying to those cases when the user is waiting to see the result of a PostBack or they wait for an action to be finished. In this highlighted cases, make sure you add a loading icon or a percentage of action completion.
Median Load Time (Fall 2012) from Strangeloop
Every Second Counts from KISSmetrics
Mobile vs. Desktop from KISSmetrics
How your brain perceives page load times from Strangeloop
In the following posts, I will give you some front-end performance optimization tips that could save your project some good seconds at page load.