Platform spec
Redbubble image requirements
Every product has its own pixel requirement — the Graphic T-Shirt is 3873 × 4814, the Premium T-Shirt is 2875 × 3900. There is no platform-wide long-edge rule and no single DPI threshold; the often-repeated "3000px" figure does not come from Redbubble. Match the target product's stated size.
Full specification
| Dimensions | set per product |
|---|---|
| Graphic T-Shirt | 3873 × 4814 px |
| Premium T-Shirt | 2875 × 3900 px |
| Platform-wide long-edge rule | none |
| Platform-wide DPI threshold | none published |
| Authoritative source | the Dimensions & Format page |
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 Redbubble 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.