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EPUB Fixer scans your EPUB for the exact errors blocking a KDP upload.
Grounded in available product and source data
A free KDP EPUB validator and auto-repair tool sounds simple, but EPUB Fixer's actual value is in what it refuses to do: guess. The site states plainly there are 'no guessed book decisions' — a correction only gets written when the fix is deterministic, meaning there's exactly one right answer rather than several plausible ones an author would need to choose between.
Every scan sorts issues into three honest categories: repairable automatically, needing manual review, or entirely out of scope. Repairable problems cover manifest wiring, navigation and cover metadata, and ZIP packaging issues like mimetype ordering — the kind of structural errors an author would otherwise have no way to interpret from a cryptic EPUBCheck error code alone. Manual-review cases include things genuinely requiring author judgment, like a broken anchor with multiple possible targets or a table-of-contents change, rather than the tool silently picking one for you.
Safety is built into the workflow itself: repairs apply to a separate copy, so the original file is never touched, and after any fix attempt the tool re-runs both its own structure scan and EPUBCheck — a download link only appears once both pass. If a file can't be automatically repaired, the tool still explains what's actually wrong rather than leaving an author guessing at a cryptic error code.
Scope is deliberately narrow: this handles reflowable EPUB 2 and EPUB 3 files up to 30MB, specifically for KDP and EPUBCheck conformance, and explicitly does not touch fixed-layout EPUBs, comics, DRM-protected files, DOCX conversion, cover design, or prose. The site notes KDP enforces stricter validation than many reading apps — Calibre is named specifically as more forgiving of the same underlying issues — which is exactly why a file can open fine in one app and still get rejected by KDP. Uploaded files auto-delete after 24 hours, and the whole tool is free with no tiered pricing.
No — it only writes a correction when the fix is deterministic, meaning exactly one correct answer exists; anything with multiple plausible options, like an ambiguous broken anchor, gets flagged for manual review instead.
No — repairs apply to a separate copy, so the original upload stays untouched, and a corrected download only becomes available after it passes both a structure scan and EPUBCheck.
KDP enforces stricter validation than many reading apps, and the site names Calibre specifically as more forgiving of exactly the kind of structural issues that pass there but still fail EPUBCheck's stricter conformance standard.
No — that's explicitly out of scope; the tool only validates and repairs existing reflowable EPUB files, not format conversion from DOCX or other source formats.
24 hours by default, after which it auto-deletes, though a manual deletion option is available if you want it removed sooner.
