One master, many surfaces
Store one web master per SKU (about 1600–2048 px WebP). Let the theme create smaller srcset steps. Extra 4000 px 'zoom' files are rarely worth the LCP cost.
Why it matters
- Themes request 2–5 widths per image.
- A huge master makes every width expensive.
- Feeds (Google Shopping) can use a separate JPEG if required.
How to do it
- Pick master width from the table below.
- Bulk convert the catalogue.
- Replace on the platform. Leave theme image settings at defaults.
Settings that work
If you only keep one file per SKU, choose 1600–2048 px / 80%.
| Surface | CSS width (typical) | Master to upload | WebP quality |
|---|---|---|---|
| PLP card | 200–400 px | 800 px | 75–80% |
| PDP main | 600–800 px | 1600 px | 80% |
| PDP zoom | viewport | 2048 px | 80–85% |
| Swatch | 32–64 px | 128 px | 85% |
| Home banner | 100vw | 1920 px | 75% |