Fill your layouts with instant placeholder images
A placeholder image is a stand-in graphic used while a design or application is still being built, before the final artwork is ready. Instead of leaving empty boxes in a mockup or waiting on real assets, you drop in a placeholder at exactly the dimensions the slot needs. This generator lets you create one at any width and height, in any background color, optionally stamped with a label such as the dimensions or a short caption, and download it as a clean PNG.
Placeholders are a staple of everyday design and development work. A designer building a landing page can fill every image slot with correctly sized blocks so the layout reads properly before the photography arrives. A developer wiring up a gallery or card grid can use placeholders to test how the interface responds to different image sizes and aspect ratios. Product teams use them in wireframes and prototypes to signal where content will go without committing to specifics. Because you control the exact pixel dimensions, the placeholder occupies precisely the space the real image will, so nothing shifts when you swap it in later.
Unlike most tools here, you do not need to upload anything to create a placeholder — you simply describe the image you want and Pixohub draws it on a canvas in your browser. That makes it instant and completely private, and you can generate as many variations as you like with no signup and no limits. The label option is handy for keeping large mockups organized, since a block reading 800x600 tells you at a glance what belongs there.
Choosing sizes, colors, and labels
Start with the exact dimensions your layout calls for. If you are building a responsive design, it often helps to generate a few placeholders at the common breakpoints — a wide hero, a square thumbnail, a tall portrait — so you can see how each slot behaves. Matching the placeholder's aspect ratio to the real content is the most important detail, because it is the aspect ratio that determines how surrounding elements flow around the image.
Color and labeling are about clarity. A neutral gray placeholder blends into a wireframe and keeps the focus on structure, while a bolder color makes a specific slot stand out during review. Adding a label — the dimensions, a component name, or a note like hero image — turns a plain block into a self-documenting piece of the mockup, which is especially useful when you are sharing a prototype with teammates or clients who need to understand what each region represents.
Once you are happy with a placeholder, download the PNG and reference it like any other image. When the final asset is ready, swap it in at the same dimensions and the layout stays exactly as designed. Because generation is free and unlimited, there is no reason to reuse a mismatched image — you can always produce a placeholder that fits the slot precisely.