svg

Three SVG images at 160x120, 800x600 and 1920x1080, each about 500 bytes. SVG is a vector format written in text, so the three files are almost the same size however big they are drawn. It is also the one image format that can contain scripts, which makes it a classic security question: an SVG uploaded to a website and shown inline can run JavaScript. Use these files to test that your site accepts .svg, that the correct MIME type (image/svg+xml) is served, and that thumbnails and resizing work. If your site allows SVG, check whether it is sanitised.