srakaranking.blogg.se - Experimental webkit features

For example, a DIV with a background color is not considered “contentful”.

First contentful paint: when the user sees something “contentful”, like an image or text.

First paint: when the user sees anything at all that’s not the browser’s default background.

Its metrics have become useful for understanding loading experience, and it is now part of Google’s Web Vitals initiative.

The Paint Timing API has been available in Chrome since version 60 (2017). The Paint Timing API measures the time it takes between the moment a user navigates to a URL and the moment the browser has displayed something. The Paint Timing API is a part of several performance APIs that allow web developers to observe and improve their web application performance. It’s an essential part of the toolset that lets us keep Wikimedia sites fast for everyone. Measuring web performance data in the field is critical to our monitoring. While we can measure this metric in a simulated environment, lab tests can never reproduce the real-world conditions of hundreds of millions of visitors. As different browsers behave differently, this means that a category of issues or bugs could negatively impact the initial rendering of pages on Safari specifically and we wouldn’t be able to know. However, it’s always been impossible to measure this in any form on Apple’s Safari web browser.īeing unable to measure such a basic event in the user experience for Safari visitors means that we are blind to an important category of performance issues for 20% of our visitors in the field. That particular feature has been available first as vendor-specific APIs, and now increasingly as the standardized Paint Timing API, initially on Chrome.

This web browser feature tells us at what point in time content started to appear on the screen for a visitor. In this instance, we decided to commission the implementation of a feature that lets us observe web performance from an end-user perspective. Yet, all major browser engines are FLOSS projects nowadays, and sometimes browser vendors have different priorities that don’t match the needs of the Wikimedia Foundation. It might seem surprising to hear that the Wikimedia Foundation is commissioning the implementation of a web browser feature. This web browser feature tells us at what point in time content started to appear on the screen for a visitor.īy Noam Rosenthal with Gilles Dubuc, Wikimedia Performance Team Background The story of how we decided to commission the implementation of Paint Timing API, a feature that lets us observe web performance from an end-user perspective.