What you upload, what we produce
Input
- DOCX — recommended, produces the cleanest output
- Google Doc — export as DOCX first
- Markdown — also recommended, ideal for technical books
- PDF — works if originally text-based; OCR available for scans
- Plain text — works for poetry, short fiction, simple structures
Output
- EPUB 3.3 (current standard) with EPUB 2 backward compatibility
- Embedded fonts (or your specified fonts if licensed for embed)
- Navigable table of contents linking to every chapter and major section
- Semantic markup — proper
h1/h2/h3, paragraphs, lists, blockquotes - Embedded cover image (we can extract from the cover file you uploaded)
- Accessibility metadata for screen readers and EU Accessibility Act compliance
- Passes EPUBCheck 5 (the official validator) and Apple iBooks Asset Guide tests
How the conversion pipeline works
1. Parse and structure
We parse your input file and detect the document structure — chapters, sections, headings, lists, images, footnotes, tables. If you’ve used proper styles (Heading 1, Heading 2, Body in Word), this is fast and precise. If your document is one giant paragraph with no styles, we fall back to heuristics and surface anything ambiguous for human review.
2. Build the EPUB skeleton
We split your manuscript into one XHTML file per chapter (so the book opens fast on slow devices), generate the OPF package file with proper metadata, the navigation document, and the spine — the table of contents the reader uses to jump around.
3. Embed assets
Cover image (resized to KDP-compatible resolution if needed), interior images (re-encoded for optimal size without quality loss), embedded fonts where licensed.
4. Auto-heal any defects
We run EPUBCheck against the result. Common defects (NCX UID mismatches, missing DOCTYPEs, broken navigation hrefs, remote resource references that aren’t allowed) are automatically repaired by our heal library — the same one we open-source for institutional partners.
5. Accessibility audit
Final WCAG 2.2 pass — alt-text presence, language declarations, semantic heading hierarchy, navigable nav-doc. Defects are flagged before delivery.
Lifetime EPUB Warranty
If a retailer ever rejects your EPUB for a technical defect — today, next year, ten years from now — we will regenerate the file at no charge. This warranty has no expiration and no cap. It’s the same warranty we offer institutional publishers.
Why we can do this: because our pipeline is automated, fixing an EPUB defect is cheap for us. We’d rather guarantee the file forever than charge you a re-conversion fee every time KDP changes a validation rule.