EPUB Fixer helps indie authors diagnose EPUB files that fail KDP, Kindle Previewer, or EPUBCheck. Upload one reflowable EPUB to see the exact affected paths, separate issues with a deterministic repair from those needing manual review, and download a repaired copy only after it passes EPUBCheck again. Scans are free, no signup is required, and uploaded files are deleted after 24 hours.

Hi Product Hunt 👋 I built EPUB Fixer around a frustrating publishing problem: an EPUB can open normally in Calibre but still fail KDP, Kindle Previewer, or EPUBCheck, and the error message often does not make the next step clear. EPUB Fixer is designed for finished reflowable EPUB 2 and EPUB 3 files. Upload one file and the report shows: • The exact affected path inside the EPUB • Whether the issue has a deterministic checked repair, needs manual review, or is outside scope • A repaired download only after the file passes EPUBCheck again It does not redesign book formatting, convert DOCX or PDF files, or guarantee KDP acceptance. The goal is narrower: help authors understand what can be repaired safely and what needs human judgment before another upload. Scanning is free, no signup is required, and uploaded EPUB files are deleted after 24 hours. I would especially appreciate feedback from self-published authors and ebook formatters: which EPUBCheck or KDP error has been the hardest for you to understand or fix?

finally something that tells me exactly which file path is breaking instead of just saying "epub is invalid," saved me a ton of trial and error on my last upload.

@serdarurim Thanks, Serdar — glad it saved you some trial and error. That’s exactly why EPUB Fixer points to the affected file path instead of stopping at “the EPUB is invalid.” If you run into another EPUBCheck error that’s especially hard to understand, I’d love to hear about it.

finally something that tells me exactly which file path is breaking instead of just saying "epub is invalid," saved me a ton of trial and error on my last upload.

EPUB Fixer

Find EPUB errors and verify safe repairs before KDP upload

Find EPUB errors and verify safe repairs before KDP upload