Validate, clean, and format your book for every major publishing platform — no account needed for most tools, no credit card ever. New to self-publishing? Start with our guide to Amazon KDP.
Run them in this order before uploading to KDP, Apple Books, or Kobo.
Scan your .docx for double spaces, straight quotes, and stacked blank paragraphs. Fix issues in the original file before conversion — easier to clean before than after.
Upload the cleaned .docx and download a valid EPUB 3.0 — chapter detection, smart quotes, and em dashes handled automatically. No Calibre, no Sigil.
Upload the EPUB and verify every structural check passes: mimetype, OPF, spine, navigation, image refs, and CSS. Get exact fixes for any error found.
Fill one form and get formatted metadata for KDP, Apple Books, IngramSpark, and Draft2Digital — copy-paste ready for each platform's publisher portal.
Upload your cover image and verify pixel dimensions, aspect ratio, DPI, and file size against Amazon KDP, Apple Books, and Kobo requirements before you upload anywhere.
Different tools for different workflows. See what each one actually covers.
| Feature | BookKraft | Calibre | Reedsy | Kindle Create |
|---|---|---|---|---|
| EPUB Validator | ✓ free, no signup — with error descriptions | Basic "Check Book"; full validation needs plugin + Java | ✗ | ✗ |
| Metadata Builder | ✓ free, no signup — KDP, EPUB OPF, IngramSpark | Manual editing only; no platform-specific templates | Metadata within writing workflow | KDP only |
| Cover Checker | ✓ free, no signup — KDP + Apple Books | ✗ | ✗ | Basic Kindle preview |
| Word Cleanup Checker | ✓ free, no signup | ✗ | ✗ | ✗ |
| DOCX → EPUB | ✓ free (account required) | ✓ free; 200MB desktop app; manual cleanup often needed | ✓ write in Reedsy, then export (not a standalone converter) | ✓ free; reflowable books only, with limitations |
| Runs in browser | ✓ | ✗ desktop app | ✓ | ✗ desktop app |
| Works offline | ✗ | ✓ fully offline, no account | ✗ | ✓ |
| Large library management | ✗ | ✓ | ✗ | ✗ |
| Integrated writing workflow | ✗ | ✗ | ✓ write + format + export in one place | ✓ format + Kindle preview |
| Price | Free (5 tools) + from $19 one-time | Free, open-source | Free | Free |
When Calibre is the better choice
Managing a large personal library, converting between many formats offline, or doing deep EPUB surgery with plugins. Calibre's desktop depth is hard to match.
When Reedsy is the better choice
Writing and formatting in one place. If you want to draft, style, and export without switching apps, Reedsy's integrated workflow is built for that.
When Kindle Create is the better choice
Publishing exclusively to Amazon. Kindle Create's live Kindle preview and KDP-optimized output are purpose-built for that platform.
Your formatted eBook works on every platform
And more...
Five tools covering the core technical tasks before publishing an ebook. Four work without an account — open the page and run them immediately, no email address, no credit card. The fifth (DOCX to EPUB conversion) requires a free BookKraft account so the converted file has somewhere to go. None of them add a watermark, attribution text, or branding to your output files. Your EPUB is yours.
Calibre is desktop software — powerful but requires installation, has a steep learning curve for new users, and its conversion output often needs manual cleanup before uploading to KDP. Reedsy Book Editor handles formatting from inside its editor and exports clean EPUB and PDF, but your manuscript lives in Reedsy's system. Kindle Create is Amazon's own desktop tool, optimized specifically for KDP but produces a Kindle-optimized file, not a standard EPUB for other stores.
BookKraft's tools run in your browser, work with the files you already have, and output files you own with no strings attached. They handle specific technical tasks — validation, metadata, cover checks, cleanup, conversion — rather than being an all-in-one editor. Use them alongside whatever writing tool you already use.
The DOCX to EPUB converter handles the most common manuscript structures: chapter headings (H1/H2), body text paragraphs, bold and italic inline formatting, scene breaks, front matter, and back matter. It normalizes smart quotes, fixes double hyphens to em dashes, strips manual formatting overrides (manually bolded paragraphs instead of styled headings), and corrects encoding issues from copy-pasted text.
It does not handle complex layouts: multi-column text, tables, footnotes as endnotes, or heavily styled print interiors. If your manuscript is a straightforward novel, narrative nonfiction, or practical nonfiction with no complex layout, the converter output will typically pass EPUB validation without additional editing.
No. None of the five tools add watermarks, attribution text, or BookKraft branding to your output. The EPUB you get back from the converter is a clean EPUB 3.0 file with your content and nothing else. Same for metadata output, cover reports, and cleanup reports — they are purely your content.
Four tools need no account: EPUB Validator, Metadata Builder, Cover Checker, and Word Cleanup Checker. Full Manuscript Mode (DOCX to EPUB) requires a free BookKraft account. No credit card required for any free tool.
KDP accepts EPUB and DOCX. The recommended format is EPUB 3.0 — use the DOCX to EPUB converter to generate it and the EPUB Validator to check it before uploading.
No catch. The four no-account tools are free with no usage limit. Full Manuscript Mode is also free with a BookKraft account. No payment required to access any free tool.
No. These tools run entirely in your browser. No desktop software to download or install. If your browser can open a webpage, the tools work — on Windows, Mac, or Linux.
A book formatting service charges $100–$400+ and takes several days. These tools are self-serve — the technical work is automated and you get results in seconds. The tradeoff: you are doing it yourself rather than handing it off. Use a formatting service if you need a heavily designed interior (print books, illustrated books, textbooks). Use these tools for standard ebook formatting.
Yes. All five tools are free. No subscription, no credit card. The EPUB Converter needs a free account; the other four need nothing at all.
The free tools cover core ebook formatting. For AI-powered manuscript cleanup, KDP keyword research, back matter generation, print-to-digital conversion, and more — explore the full BookKraft AI toolkit. One-time purchase, no monthly fees.