Are your images slowing the page down?
Images are usually the largest thing on a page and the easiest to fix. Legacy formats, missing srcset and oversized files are the three reasons a page is slow on a phone while it looks fine on your laptop.
Reads the images on a sample of pages, checks format and srcset, and measures a few for weight. Nothing is stored.
How this check works
Shipwork parses the images on a sample of your pages and reports three things: whether any use a modern format (WebP or AVIF), whether they carry a srcset so phones do not download desktop-sized files, and whether the heaviest ones exceed a sensible size. It reads raw HTML and a few image headers, so it sees what a browser actually has to fetch.
Questions
- Why WebP or AVIF?
- They are 25-50% smaller than JPEG or PNG at the same quality, and every modern browser supports them. Smaller images mean a faster largest contentful paint.
- What is srcset?
- A list of image sizes a browser can choose from. Without it, a phone downloads the full desktop image, which is slower and wastes data.
- How big should an image be?
- There is no single number, but product and hero images over a few hundred KB are usually compressible without visible loss.