Free vs Paid Book Cover Tools: What You Actually Get
Where a free preview stops being useful, what a paid export should fix, and when a human pass is worth $19.
A free preview is a decision tool
Free cover generators are useful for the decision, not the file: does this genre direction and title zone work? A watermark makes the preview unusable for publishing, which is the point. Judge composition and readability, not polish, and do not put a watermarked concept on a store page.
A paid export should fix the file, not the idea
The paid step is worth it when it removes the watermark, sizes the file for your trim, and gives you a usable format. If a paid file is still a screenshot with soft edges and no size control, you paid for a preview. Check the dimensions and file type before you trust it.
The human pass is for type and judgment
AI artwork can be strong while the title setting, spacing and small details are weak. A short human polish is worth $19 when it sets a clean text layer, keeps the title readable at thumbnail size, and checks the file against the printer's specs. It is not worth it if you only need one quick concept.
spine width — Free tools usually stop at the image. The part they leave out is the arithmetic: page count and paper decide the spine, and the calculator returns it in seconds.