What information is tracked by PLT?


The following PLT information is tracked for each page request, along with the full path and name of the page:



Latency is the measure of elapsed time from the point at which the user initiates a new page request, to the point at which the requested page begins to load.


Latency is affected by a number of factors including the type and quality of each user's Internet connection, their path through the Internet to your network, the quality and performance of your network, and the overall responsiveness of your backend servers and application itself.


Latency can have a significant impact on the page load times experienced by site visitors. Therefore one cannot measure page load times in a vacuum based solely on the size of the content which comprises a given web page.


For example, assume a database query involved in rendering a page takes longer than expected to complete. Or that a network issue has surfaced causing higher latency than normal. Such conditions may have a profound impact on the page load times experienced by your visitors.


Therefore the ability to monitor your page load times which include latency, as well as latency as its own individual component of page load times, helps you identify performance issues that impact your visitor's web experience.


Intra-page Load Time

Intra-page load time is the measure of elapsed time from the point at which a requested page begins to load, to the point at which the page and all its components finish loading. Unlike latency, Intra-page load time is directly impacted by the size and content of each web page.


Intra-page load time measurements provide details on how fast each page is actually loading for users. These measurements are very helpful in determining whether the actual page load times are meeting your desired response times.


For example, assume you have designed your home page to load in under five seconds under normal conditions for most users. In your testing, you may find that the page loads in under five seconds each time you or a colleague tries the page. However, once your page is accessed "in the wild" by real users with varying connection types and conditions beyond your control, what will the actual page load times be?


Using Intra-page load time, in conjunction with Latency, you can now know exactly what percentage of your audience is indeed meeting your page load time goals. When goals are not met, you can make updates to the page design and monitor the new results to see what actual improvements have been made.


HitType (page view classification)


Along with the actual Latency and Intra-page load times measurements, BrowserHawk also provides a HitType. The HitType is a classification which describes the conditions under which the measured PLT data was obtained.


The HitType is an important data point, as it enables you to analyze the PLT measurements in their proper context. For example, pages that are viewed from cache will have an Intra-page load time that is much faster than pages retrieved from the server.


Without separately distinguishing cached pages, the Intra-page load times would be contaminated by cached page results, artificially lowering the measurements significantly. At the same time, Intra-page load times for cached pages have significant value when analyzed separately, so it is important that this data is kept for analysis of your caching strategy.


See Also:

About Page Load Time Monitoring