Full guide
The print-on-demand file spec guide
The four major platforms differ more than most sellers expect. This page puts them side by side and links out to the detail and the checker for each.
Side by side
| Printful | per product · ≥150 DPI · ≤200 MB · ≤20,000 px |
|---|---|
| Printify | no platform-wide size · 300 DPI recommended · ≤100 MB |
| Redbubble | per product · Graphic Tee 3873×4814 · Premium Tee 2875×3900 |
| Merch by Amazon | exactly 4500×5400 · 300 DPI · sRGB PNG |
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.
One file that satisfies all four
If you list across multiple platforms, build to the strictest of them: 4500 × 5400 pixels, 300 DPI, transparent PNG, under 25 MB. That single specification clears every one of the four. Files optimised for one platform in isolation tend to fail somewhere else.
By platform
Already rejected?
Frequently asked questions
Can one file work across all four platforms?
Yes. Build at 4500 × 5400 pixels, 300 DPI, transparent PNG, under 25 MB, and it clears all four checks.
Which platform catches sellers out most often?
Redbubble. It rejects almost nothing, so problems only surface when a customer receives the product — and its highest-margin categories are the large formats most sensitive to resolution.