<img Decoding="async" Class="alignleft" Src="ht... Apr 2026

249: Decoding async, tree rings, and flexbox gap - CSS-Tricks

: It allows text and other non-image content to appear sooner, rather than waiting for large images to be fully processed. The Trade-off: LCP and "Popping" <img decoding="async" class="alignleft" src="ht...

The attribute decoding="async" in an tag is a performance-focused hint that tells the browser to decode image data off the main thread. This prevents the CPU-intensive process of converting a compressed file (like a JPEG) into raw pixels from blocking the rendering of other critical content, such as text or interactive elements. Why decoding="async" Matters 249: Decoding async, tree rings, and flexbox gap

When a browser downloads an image, it must decode it before it can be displayed. By default, many browsers perform this synchronously, meaning they wait for the image to decode before showing the rest of the page content. Why decoding="async" Matters When a browser downloads an

: Because the browser might paint the rest of the page before the image is ready, the image may "pop in" suddenly after the surrounding text is already visible.