Lulu Cover Checker
Check your Lulu paperback cover before you upload it. Enter your trim size and page count, drop in your cover export, and see whether the size, spine and resolution match Lulu's specs, with the bleed and 0.5 in safety margin drawn on your artwork.
What Lulu checks for
Cover width. Lulu's spine is (pages ÷ 444) + 0.06 in, which is wider than a KDP spine on white paper. A cover made for KDP usually needs resizing before Lulu will accept it. See KDP vs Lulu spine width.
Bleed and safety margin. Lulu needs 0.125 in of bleed on every outside edge and asks you to keep text and important art 0.5 in inside the trim, more than KDP's 0.125 in.
Resolution. Covers print at 300 DPI. Below that, images and text can look soft.
Specs last checked against Lulu's published specs in September 2026.
Frequently asked questions
What size should my Lulu cover image be?
Trim width × 2 + spine + 0.25 in bleed, by trim height + 0.25 in, at 300 DPI. The spine is (pages ÷ 444) + 0.06 in. For example, a 6 × 9 in book with 300 pages needs a 12.986 × 9.250 in cover, which is 3896 × 2775 pixels.
Why does Lulu say my cover is the wrong size?
Usually the spine. If your page count changed, or the cover was made for KDP, the width no longer matches Lulu’s spine formula. The checker tells you which page count your image actually fits.
Is my cover uploaded anywhere?
No. The checker reads your image in your browser, and the file never leaves your device.