Platform spec
Merch by Amazon image requirements
Exactly 4500 × 5400 at 300 DPI, matching a 15″ × 18″ print area. PNG with a transparent background, exported as sRGB. The 25 MB file ceiling still needs confirming against the current official page.
Full specification
| Required size | 4500 × 5400 px (exact match) |
|---|---|
| Physical size | 15″ × 18″ at 300 DPI |
| File format | PNG, transparent background |
| Colour space | sRGB |
| File size limit | 25 MB — confirm against the current upload page |
| Typical real size | 30 – 60 MB |
Why the recommended size matters more than the DPI figure
DPI is a ratio, and a ratio without a physical size tells you nothing. Rather than remembering "it needs 300 DPI", remember this platform's recommended pixel dimensions — get the pixel count right and the DPI follows. The reverse never works: a file tagged 300 DPI with too few pixels fails everywhere.
Batch, auto-fix and exports
Checking one file at a time is free and always will be. Batch checking up to 100 files, one-click exports sized for every platform, and CSV reports are part of Seller.
Exports are padded and centred to each platform's size on a transparent canvas. Nothing is ever upscaled — a file enlarged to pass a dimension check still prints soft, which is the failure this tool exists to prevent.
Frequently asked questions
Does Merch by Amazon need a transparent background?
Yes. Without an alpha channel the white background is treated as ink, and on a dark garment it prints as a visible white box around the artwork.
How reliable are these numbers?
They come from the platform's published upload requirements. Platforms revise specs, so check the official documentation before an upload that matters.