Fit modes
| Mode | What happens | Use for |
|---|---|---|
| Contain | Pads with white. Nothing cropped. | Product photos, listings |
| Cover | Crops the edges to fill the frame. | Banners, thumbnails |
| Stretch | Distorts to the exact size. | Rigid upload forms |
Formats
| Format | Best for | Trade-off |
|---|---|---|
| JPEG | Photos, anything with a size limit | No transparency |
| PNG | Logos, screenshots, transparency | Large for photos |
| WebP | Web use, ~25–30% smaller than JPEG | Some marketplaces reject it |
PNG to JPEG flattens transparency onto white, since JPEG has no alpha channel.
Hitting an exact file size
Set Compression to Hit a target file size for forms that cap uploads at 100 KB, 200 KB or 500 KB. It binary-searches JPEG quality for the best fit under your cap. If even minimum quality overshoots, it says so — that means you need smaller dimensions, not more compression.
Limits
- HEIC isn't supported. No browser decodes it. On iPhone: Settings → Camera → Formats → Most Compatible.
- Very large images can fail on iPhone. Mobile Safari caps canvas memory around 16 megapixels.
- Upscaling won't add detail. Start from the largest original you have.