Which browser is not supported for the "Visually complete" metric due to lack of resource timings?

The "Visually complete" metric is used to determine when the majority of the content on a webpage has finished loading, providing insights into user experience. This metric relies on the availability of resource timing data, which helps in measuring the individual loads and rendering times of resources within the webpage.

In the case of Safari, it does not fully support resource timing APIs like Chrome, Firefox, and Edge do. This lack of support affects the ability to gather the necessary data to accurately measure and report the "Visually complete" metric.

In contrast, Chrome, Firefox, and Edge have established support for resource timings, allowing for a comprehensive assessment of webpage performance and user experience metrics, including visibility tracking. Therefore, the limitation within Safari is what makes it unsuitable for "Visually complete" calculations, emphasizing the critical role of resource timing data in performance monitoring tools like Dynatrace.