Best EPUB Formatting Tools for Indie Authors

Vellum is the best EPUB formatting tool if you are on a Mac and can afford the one-time cost. Atticus is the best cross-platform alternative. Calibre is the best free option. Everything else is situational.

Those three recommendations cover 90% of indie authors. The remaining 10%, authors with complex non-fiction, technical content, or very specific design requirements, need Sigil, InDesign, or a combination of tools.

This guide breaks down six popular formatting tools, compares them head-to-head, and helps you choose based on your specific needs and budget.

Tool Comparison Overview

Vellum: The Gold Standard (Mac Only)

Vellum has earned its reputation as the tool that makes beautiful books with minimal effort. You import your manuscript (DOCX, TXT, or other common formats), choose a style, make adjustments, and export. The output is consistently clean, well-structured EPUB 3 with proper metadata and navigation.

What Vellum Does Well

Gorgeous defaults. Vellum's built-in styles look professional without any customization. Chapter headings, scene breaks, first paragraphs, and back matter all receive thoughtful styling that looks good across all e-readers.

Simultaneous print and ebook. The $299.99 tier exports both reflowable EPUB and print-ready PDF from the same source, keeping your formats in sync. This saves significant time if you publish in both formats.

Automatic structure. Vellum generates proper heading hierarchy, navigation documents, and semantic markup automatically. It also adds basic accessibility metadata to the OPF. This means fewer validation errors out of the box.

Inline images. Inserting images into your chapters is drag-and-drop simple. Vellum handles sizing and format conversion.

Vellum's Limitations

Mac only. There is no Windows version, and running Vellum in a Mac virtual machine on Windows violates Apple's terms of service (and is unreliable). If you are on Windows, Vellum is not an option.

Limited customization. You cannot edit the HTML or CSS directly. If Vellum's built-in styles do not do what you need, you are stuck. This is rarely an issue for fiction, but non-fiction authors with complex formatting needs may hit walls.

No alt text editor. Vellum does not provide a way to add alt text to images within the app. You need to edit the output EPUB in Sigil or use a tool like Rahatt to inject alt text after export.

Price. At $249.99 (ebook only) or $299.99 (ebook + print), Vellum is the most expensive option on this list. However, it is a one-time purchase with unlimited exports, so the per-book cost drops quickly.

Who Should Use Vellum

Fiction authors on Mac who want professional results with minimal technical involvement. Also excellent for memoir, short story collections, and poetry. If you publish more than two books per year, the time savings alone justify the price.

Atticus: The Cross-Platform Contender

Atticus launched in 2021 as a direct competitor to Vellum, with one critical difference: it runs in a web browser, so it works on Windows, Mac, Linux, and Chromebooks. It also includes a writing environment, making it a combined writing and formatting tool.

What Atticus Does Well

True cross-platform. Atticus runs as a desktop app built on web technology, available for Windows, Mac, and Linux. Your projects sync via the cloud, so you can work from any computer.

Writing and formatting combined. Unlike Vellum (formatting only), Atticus includes a distraction-free writing editor. You can draft, edit, and format in one tool, reducing export/import friction.

Competitive pricing. At $147 one-time (including both ebook and print export), Atticus is significantly cheaper than Vellum and includes more features out of the box.

Custom chapter styles. Atticus offers more style customization than Vellum, including the ability to create custom chapter heading designs and body text styles.

Atticus's Limitations

Newer ecosystem. Atticus is still younger than Vellum, and while it has matured rapidly, some features are less polished. The template library is smaller, and edge cases in formatting occasionally produce unexpected results.

Image handling. Image insertion works but is less intuitive than Vellum. Positioning options are limited for inline images.

No direct HTML/CSS editing. Like Vellum, you cannot access the underlying code. For most authors this is fine, but it limits what power users can do.

Who Should Use Atticus

Windows authors who want a Vellum-like experience, and Mac authors who want writing and formatting in a single tool. Also a strong choice for authors on a budget who want professional output without learning HTML.

Calibre: The Swiss Army Knife

Calibre is an open-source ebook management application that has been a staple of the indie publishing community since 2006. It converts between virtually every ebook format, manages ebook libraries, and includes a built-in editor for EPUB files.

What Calibre Does Well

Format conversion. Calibre converts between EPUB, MOBI, AZW3, PDF, HTML, TXT, RTF, DOCX, and many more formats. Its conversion engine is highly configurable, with options for table of contents detection, chapter splitting, font embedding, and more.

Batch processing. If you need to convert or modify dozens of ebooks at once, Calibre handles this efficiently. This is invaluable for authors with large backlists that need updating.

Free and open source. No cost, no subscription, no feature limits. It runs on Windows, Mac, and Linux.

Built-in editor. Calibre includes a visual EPUB editor that lets you modify HTML, CSS, and metadata. It is not as powerful as Sigil, but it handles common editing tasks.

Metadata management. Calibre excels at organizing ebook metadata, titles, authors, tags, covers, descriptions. It can fetch metadata from online databases and apply it in bulk.

Calibre's Limitations

Formatting from scratch is painful. Calibre is excellent for converting and tweaking existing files. Creating a beautifully formatted EPUB from a raw manuscript is possible but requires significant manual work.

Output quality varies. DOCX-to-EPUB conversion can produce clean results or messy results, depending on how the source document was formatted. Complex Word documents with heavy styling often convert poorly.

Interface. Calibre's interface is functional but dated. It was designed for power users, and new authors may find it overwhelming.

Who Should Use Calibre

Authors who need a free conversion tool, those managing large ebook libraries, and anyone who needs batch processing. Calibre is also the right choice for converting EPUB 2 to EPUB 3. It pairs well with other tools, use Vellum or Atticus for initial formatting, then Calibre for conversion and management.

Sigil: The Power User's Editor

Sigil is a free, open-source EPUB editor that gives you direct access to the HTML, CSS, and metadata inside an EPUB file. It is not a formatting tool in the traditional sense, it is an IDE for EPUB files.

What Sigil Does Well

Full control. You can edit every file inside an EPUB: HTML content, CSS stylesheets, OPF metadata, navigation documents, and images. Nothing is hidden or abstracted away.

Validation integration. Sigil includes built-in EPUBCheck validation. You can check your EPUB for errors without leaving the editor.

Plugin system. A community of plugins extends Sigil's capabilities. Popular plugins include tools for accessibility checking, CSS optimization, and automated table of contents generation.

Regex search and replace. Sigil's find-and-replace supports regular expressions across all files, making batch changes fast. Need to change every <h4> to <h3> across 30 chapters? One regex operation.

Split and merge. You can split long HTML files into chapters or merge short files together. This is essential for managing reading performance, e-readers struggle with very large HTML files.

Sigil's Limitations

Steep learning curve. You need to understand HTML, CSS, and EPUB structure to use Sigil effectively. It is not a word processor, it is a code editor specialized for EPUB.

No visual preview. Sigil has a preview pane, but it does not perfectly replicate how e-readers render content. You still need to test on actual devices or in dedicated previewers.

No print output. Sigil is EPUB-only. If you need print PDFs, you will need another tool.

Who Should Use Sigil

Authors with HTML/CSS knowledge who need fine-grained control over their EPUB output. Technical writers, non-fiction authors with complex layouts, and anyone who needs to fix specific issues in an existing EPUB. Sigil is also the best tool for adding accessibility features (alt text, ARIA attributes, heading corrections) to EPUBs exported from other tools.

Scrivener: Writer First, Formatter Second

Scrivener is primarily a writing tool, not a formatting tool. Its ebook export is functional but limited compared to dedicated formatting software.

What Scrivener Does Well

Writing environment. Scrivener's binder, corkboard, and research panel make it an excellent tool for drafting and organizing complex manuscripts. Most authors who use Scrivener love the writing experience.

Compile flexibility. Scrivener's Compile feature exports to EPUB, DOCX, PDF, and other formats. You can create custom compile formats with detailed control over how sections are styled.

Affordable. At $49 one-time (with frequent sales), Scrivener is the cheapest paid option on this list.

Scrivener's Limitations

EPUB output quality. Scrivener's EPUB export is adequate but not beautiful. The default styles are plain, and achieving polished results requires significant Compile customization, which has its own steep learning curve.

EPUB version inconsistency. Depending on your Scrivener version and compile settings, output may be EPUB 2 or EPUB 3. Verify your output format and consider converting to EPUB 3 with Calibre if necessary.

No post-export editing. Once you have exported, any changes to the EPUB require re-compiling from Scrivener. You cannot make quick fixes to the EPUB directly.

Who Should Use Scrivener

Authors who already write in Scrivener and need basic EPUB export. For professional formatting, most Scrivener users export to DOCX and import into Vellum or Atticus for final formatting. This "Scrivener for writing, Vellum for formatting" workflow is one of the most popular in indie publishing.

Reedsy Book Editor: The Free Web Option

Reedsy's free online book editor provides a clean writing and formatting environment with professional EPUB export. It is part of Reedsy's marketplace for publishing professionals.

What Reedsy Does Well

Truly free. No cost, no feature limits, no export fees. Reedsy makes money from its marketplace for editors, designers, and marketers, the book editor is a lead generation tool.

Clean output. Reedsy's EPUB export produces well-structured EPUB 3 files with proper navigation and metadata. The formatting is simple but clean.

Cloud-based. No software to install. Works in any modern web browser.

Collaboration features. You can invite editors and co-authors to work on your manuscript within the Reedsy editor.

Reedsy's Limitations

Limited style options. You get a handful of chapter styles and minimal control over typography. Fine for novels, limiting for non-fiction.

Internet required. No offline access. If your internet goes down, you cannot work.

No image support for inline content. Reedsy handles cover images but offers limited support for inline images within chapters.

Export lock-in concerns. Your manuscript lives on Reedsy's servers. While you can export at any time, you are dependent on the service remaining available.

Who Should Use Reedsy

First-time authors who want professional results without spending money or learning new software. Also useful for authors who want to test the self-publishing process before investing in a dedicated formatting tool.

Feature Deep Dive: Accessibility Support

Since accessibility now directly affects your book's visibility on Amazon and compliance with the European Accessibility Act, tool support for accessibility features matters.

No single formatting tool produces a fully accessible EPUB out of the box. The gap is typically in alt text (most tools do not have an alt text editor) and accessibility metadata (most tools add only basic metadata).

This is where a post-formatting validation and repair step becomes essential. Tools like Rahatt can scan your formatted EPUB, identify accessibility gaps, and fix many of them automatically, including injecting accessibility metadata, correcting heading hierarchy, and improving link contrast. Our EPUB validation guide covers the complete post-formatting workflow.

Recommended Workflows

For Fiction Authors

Budget workflow: Write in Google Docs or Word, export to DOCX, import to Reedsy Book Editor, export EPUB 3, validate with Rahatt.

Standard workflow: Write in Scrivener or Word, import to Atticus ($147), format and export EPUB 3, validate with Rahatt.

Premium workflow: Write in Scrivener, export DOCX, import to Vellum ($299.99), export EPUB 3 and print PDF, validate with Rahatt.

For Non-Fiction Authors

Simple non-fiction (business, self-help): Same as fiction workflows above. Atticus or Vellum handle these well.

Complex non-fiction (textbooks, technical, reference): Write in Word or LaTeX, export to EPUB with Calibre, edit in Sigil for fine-tuning, validate with EPUBCheck and Rahatt.

For All Authors: The Post-Formatting Checklist

Regardless of which tool you use, run this checklist after formatting:

1. Open the EPUB in an e-reader app (Apple Books, Calibre viewer, Thorium) and read through at least 3 chapters
2. Check the table of contents, does every chapter appear? Are the titles correct?
3. Check images, do they display correctly? Are they properly sized?
4. Run EPUBCheck, fix all errors, review warnings
5. Run a Rahatt scan, fix any accessibility issues and check your suppression risk score
6. Preview in Kindle Previewer 3 if publishing on Amazon

For the complete validation process, see our EPUB validation guide. For details on what metadata your EPUB should contain, see our ebook metadata guide.

Frequently Asked Questions

Can I use a free tool and still get professional results?

Yes. Calibre and Reedsy Book Editor both produce clean EPUB files suitable for professional publishing. The trade-off is time and effort, free tools require more manual work to achieve the same polish that paid tools provide automatically. For a novel with no images and standard formatting, Reedsy's output is genuinely professional. For anything more complex, you will likely need Sigil for post-export editing.

I am on Windows. What is my best option?

Atticus ($147, one-time) is the closest equivalent to Vellum on Windows. If you want a free option, use Reedsy for initial formatting and Sigil for cleanup. The Calibre + Sigil combination is also powerful but has a steeper learning curve.

Do I need different tools for ebook and print formatting?

Vellum and Atticus both export ebook (EPUB) and print (PDF) from the same source. If you use a tool that only exports EPUB, you will need a separate tool for print layout, typically InDesign or Affinity Publisher. Some authors use Amazon's free Kindle Create for Kindle-specific formatting and a separate EPUB tool for other retailers.

How do I add alt text to images if my tool does not support it?

Export your EPUB, then either: (1) open it in Sigil and manually add alt attributes to each <img> tag, or (2) upload it to Rahatt and use the AI-powered alt text feature, which generates context-aware descriptions and lets you review them before applying. Option 2 is significantly faster for books with many images. See our alt text guide for best practices on writing effective alt text.

Which tool produces the most accessible EPUB?

None of them produce a fully accessible EPUB without additional work. Vellum and Atticus come closest by auto-generating navigation documents and basic metadata, but they lack alt text support and complete accessibility metadata. The most reliable path to a fully accessible EPUB is: format with your preferred tool, then validate and repair with Rahatt. This adds 10-15 minutes to your workflow and can improve your Amazon visibility score from medium-risk to low-risk.