Hey Product Hunt! 👋

I'm Walid, creator of EPUB Inspector.

Like many developers, indie authors, and digital publishers, I spent years wrestling with ebook validation. If you’ve ever tried publishing an EPUB to Apple Books, Kobo, or KDP, you know the nightmare: cryptic EPUBCheck codes, broken manifests, and endless manual tweaking in Sigil or Calibre.

Most tools either require heavy desktop software, charge subscriptions for basic fixes, or force you to upload your unpublished manuscripts to a third-party server.

I built EPUB Inspector to fix this once and for all—right inside your browser.

At the core of the suite is the EPUB Fixer engine, built to eliminate validation headaches without guesswork:

🔧 128 Error Codes Auto-Fixed: One-click automated resolution for deterministic structural faults (e.g., RSC-005, PKG-026, OPF-014, HTM-004, CSS-002, NCX-001, NAV-010, and more...)

🎯 32 Guided Repairs: For ambiguous issues that need an author's judgment (OPF-029, RSC-007, PKG-020, ACC-002...), the tool presents a visual diff so you confirm the exact resolution.

🔒 100% Client-Side Privacy: Your files never touch a remote server. Everything—validation, WebAssembly repair, CSS inspection, and packaging—runs entirely in local browser memory.

⚡ Complete Toolkit: Real-time EPUB 2 to EPUB 3 conversion testing, metadata & cover editing, and instant visual structure exploration.

It's completely free, requires no sign-up, and is built on open web standards.

I’d love for the PH community, authors, and frontend devs to put their broken EPUBs through it!

What’s the most frustrating EPUBCheck error code you’ve had to resolve? Any tools you’d like to see next?

Looking forward to your thoughts and feedback! 🚀