Platform spec
Merch by Amazon image requirements
Any PNG larger than 485 × 485 is accepted — the exact-size rule is gone, and the design editor scales and centres artwork for you. Aim for at least 4500 px on the long edge so there is room to scale down, keep the file under 25 MB, export RGB, and trim the surrounding transparent pixels so the centring tools measure your artwork rather than empty space.
Full specification
| Minimum size | 485 × 485 px — the only hard dimension rule |
|---|---|
| Recommended size | 4500 px or more on the long edge |
| Physical size | 4500 × 5400 = 15″ × 18″ at 300 DPI |
| File format | PNG, RGB, 8 bits per channel |
| File size limit | 25 MB — stated in writing |
| Typical real size | 30 – 60 MB |
| Before exporting | Trim the empty transparent margin |
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
Everything above is free for one file at a time, and always will be. Doing it to a whole folder — batch checking up to 100 files, one zip with every platform file for every design, and a CSV report — is 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
What size should an image be for Merch by Amazon?
Anything above 485 × 485 pixels is accepted and scaled to fit — the old exact-size requirement no longer applies. Aim for 4500 × 5400 so there is room to scale down rather than up.
What is the maximum file size on Merch by Amazon?
25 MB. Going over it is one of the few things that reliably stops an upload.
Can I upload a WebP to Merch by Amazon?
No. Merch by Amazon accepts PNG. WebP is not on the list at any of the four platforms, and several design tools now export it by default — so this catches people who got everything else right. Re-export as PNG.
Is 300 DPI enough for Merch by Amazon?
DPI on its own is not a quantity — it only means something once you fix a physical size. Merch by Amazon advises 300 DPI, measured across the 15″ × 18″ print area, which works out to 4500 × 5400 pixels. A file tagged 300 DPI with fewer pixels than that is not 300 DPI where it counts.
Will Merch by Amazon reject a low-resolution file?
No. Merch by Amazon publishes no density at which an upload is refused; low resolution produces a warning at most. That is the trap — the file goes through, the product lists, and the problem surfaces when a customer opens the parcel.
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 current are these numbers?
Read off Best Practices — Artwork tips (sign-in required) on 2026-09-14. Platforms revise specs quietly — Merch by Amazon dropped its exact-size requirement without announcing it — so check the source before an upload that matters.