Compare two proofs
Fixed a typo and re-exported, and now you're not sure what else moved? Drop in the old and the new PDF of your interior: every word that changed, the pages that reflowed because of it, whether the page count changed (so your spine and cover need changing too), and any page that looks different though its words didn't. It works for covers too (two cover PDFs or images, with the differences shown in red), and for ebooks: two EPUBs, chapter by chapter, with any pictures or book details that changed.
Compared in your browser. Your files aren't uploaded to Bervet and nothing is kept. Free for members.
The new cover, with what's different from the old one in red.
Why check
One added word can push a line onto the next page, and then every page after it. That can put a chapter opening on a left-hand page, leave one line of a paragraph alone at the top of a page, or add a page, and KDP and IngramSpark work out the spine width from the page count. Before you upload a corrected file, check that only what you meant to change has changed.
What it can't see
It compares the text the PDF contains and how each page looks. Text that's part of a picture (a scanned page, a title set as an image) is compared as a picture, not as words. A new font with the same words shows up as a changed page, not as a text change. If the page count changed, check the new spine width with the spine calculator.
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