Placeholder Image

They are used in web development for layout verification, wireframes, prototypes, and design mockups before actual images are ready.

Yes, by default the image dimensions are shown, but you can change it to any text you want. Text color and font are also customizable.

A single gray rectangle tells visitors the site is unfinished, and on a product page it makes people hesitate to buy. It costs you in search too: the blank placeholder gets indexed in Google Images, and if the image field of your Product structured data points at that URL, the page can lose its rich-result eligibility. Before every release, grep the whole codebase for strings like placeholder or via.placeholder.

Match the exact aspect ratio of the image that will eventually sit there. If the real picture loads at a different shape, everything below it shifts down, and that pushes up your Cumulative Layout Shift score in Google's metrics. The pixel dimensions need not match, but the ratio must — and put width and height attributes on the img tag so the browser reserves the space before the file arrives.