Free tools for coloring book and KDP creators
Clean up line art, remove backgrounds, size your paperback cover and check print resolution. No signup, no uploads, no watermarks.
Background Remover
Turn the white (or any solid color) behind your art into transparency. Runs in your browser.
Line Art Cleaner
Turn gray, fuzzy line art into crisp pure black and white, ready for coloring book pages.
KDP Spine & Cover Calculator
Spine width and full wrap cover size for your paperback, in inches, millimeters and pixels.
Print Resolution Checker
Find out if your image has enough pixels to print sharp at your page size.
Why these tools exist
If you make coloring books, activity books, journals or any other paperback for print on demand, you spend a surprising amount of time on small chores that have nothing to do with drawing. A scan comes back gray instead of black. An AI-generated page has a white box around it. The cover file is the wrong width because the page count changed at the last minute. An image looks fine on screen and prints soft. Each of these takes a few minutes to fix, but they add up over a whole book.
This site collects the fixes in one place. Each tool does one job and does it in your browser, so your artwork stays on your computer. Nothing is sent to a server, which also means the tools keep working even on a slow connection once the page has loaded.
What is here right now
The Background Remover makes the white or colored area around your art transparent so you can place it on a cover, a sticker sheet or a mockup. The Line Art Cleaner pushes every pixel to pure black or pure white, which is what a coloring book page wants. The KDP Spine & Cover Calculator works out spine width and the full wrap cover size from your trim size, page count and paper. The Print Resolution Checker tells you whether an image has enough pixels for the page size you picked.
How the tools handle your files
When you choose an image, your browser reads it and does the work locally using the same technology that draws web pages. The file is not uploaded and we never see it. Close the tab and it is gone. You can read the details in the privacy policy.
Accuracy and limits
The spine and cover numbers come from the per-page paper thickness that Amazon KDP publishes, plus the standard 0.125 inch bleed. KDP can change these values, and its own cover template generator is the final authority, so always compare against it before you upload a cover. The image tools are built for graphics, line art, logos and scans. They are not photo editors, and they will not cut a person out of a busy photograph.
Something missing?
If there is a small chore in your publishing workflow that you wish a tool handled, tell us. The next tools on the list are driven by what people ask for.