On mobile, the highest impact on a page load time is the latency of connection. This is the time it takes to receive a response from the server.
For mobile, the average latency is 10 times higher than an average broadband connection. This takes around 4.5 seconds of the total load time just for the latency. Even in mobile, the total load time expectation is of 5 seconds, which leaves 0.5 seconds to load all the website elements. This requires that not only the visual interface is optimised but also the page size.
Images represent on average 64% of the page weight, they can bring high savings by resizing them to the necessary dimensions. Just by choosing the right format with the necessary quality levels and use special image optimisation software to remove unnecessary information from the files.
Since the content that is not shown in the mobile layout is still loaded, content strategy can make a significant impact.
In combination with browser or agent detection to serve just the required content according to the device.
The server can compress files on request before dispatching them. Also, it is possible to leverage the browser caching by incrementing the expiration date of assets that don’t vary often.
Concatenation and Minification