Bookfolio Fixer – free online EPUB validator + safe auto-repair (feedback wanted)

[BookfolioElara]

Hello all. Disclosure first: I'm part of the team behind Bookfolio (an indie ebook store), and this is our tool.

**Bookfolio Fixer** (https://fixer.bookfolio.io) is a web-based EPUB checker. It validates against the EPUB specification and then:
- **repairs automatically** only the mechanical things: mimetype packaging, items missing from the OPF manifest, a missing EPUB 3 nav document (built from the NCX), duplicate IDs and unescaped ampersands
- **reports but doesn't touch** anything that needs judgement: broken links to missing resources, missing accessibility metadata, DRM and metadata decisions
- explains every EPUBCheck error code in plain English

There's also a free **EPUB Inspector** (https://fixer.bookfolio.io/tools/epub-inspector) that shows the metadata, cover size, TOC, scripts and accessibility details, plus a rough store-acceptance view for Amazon/Apple/Kobo. Nothing is kept.

Limits, to be upfront: 3 fixes without an account, 10/month with a free account. Uploaded originals are deleted after processing, and the repaired file stays downloadable for 10 minutes.

It isn't meant to replace Sigil or a careful hand edit. It's meant for the "the store rejected my file and I don't know why" moment. I'd value this forum's view on which auto-repairs you'd consider safe, and I'd be grateful for any file it handles badly (PM me if it can't be shared publicly).