Marks the image for observation by the PerformanceElementTiming API. The value given becomes an identifier for the observed image element. Weiher also the elementtiming attribute page. Try it Yourself » If a browser cannot find an image, it will display the value of the alt attribute: Microsoft and DuckDuckGo have https://marcomwhsb.blogcudinti.com/28741763/the-ultimate-guide-to-image