As a self-published author and ebook enthusiast, I've tried my share of tools for crafting EPUB files. In 2026, with so many paid options and AI-assisted editors popping up, one free, open-source standout still holds its ground: Sigil. This multi-platform EPUB editor has been around for years, but it's far from outdated—it's actively maintained and packed with features that make it a favorite for indie authors, editors, and anyone who wants full control over their ebooks.
Sigil is a free, open-source editor designed specifically for EPUB 2 and EPUB 3 formats. Developed by a dedicated volunteer team and hosted on GitHub, the latest releases (up to version 2.7.0 as of late 2025) show it's still evolving with Qt6 support, plugin enhancements, and bug fixes.
Key Features That Make Sigil Shine
Sigil strikes a perfect balance between ease of use and power. Here's what stands out:
WYSIWYG and Code Views: Switch seamlessly between a word processor-like Book View, a live Preview, and direct HTML/CSS code editing. This is gold for fine-tuning without messing up your formatting.
Built-in Tools: Automatic Table of Contents generation, metadata editing, spell checking, and EPUB validation (using epubcheck under the hood).
File Management: The Book Browser pane makes organizing chapters, stylesheets, images, fonts, and media straightforward.
Plugins Support: Extend functionality with Python plugins for tasks like advanced searches or custom validations.
Cross-Platform: Runs smoothly on Windows, macOS, and Linux, with options like AppImage for easy installation.
The interface is clean and customizable—you can dock/undock panels, rearrange toolbars, and even use dark mode. The Preview window gives a realistic reader view, complete with inspector tools.
There's also PageEdit, a companion app for pure visual XHTML editing, which integrates nicely if you prefer avoiding code entirely.
Pros and Cons
Pros:
- Completely free and open-source (GPLv3).
- Produces clean, standards-compliant EPUBs—no bloat.
- Powerful for advanced users (direct code access, CSS control).
- Active community support via MobileRead forums.
- Regular updates keep it compatible with modern EPUB standards.
Cons:
- Steep learning curve if you're new to HTML/CSS—it's not as "hand-holding" as word processors like Microsoft Word or Google Docs.
- No built-in conversion from other formats (pair it with Calibre for that).
- WYSIWYG view isn't as polished as some commercial tools.
Alternatives?
Calibre has a solid built-in editor, but many prefer Sigil for precise EPUB tweaking. Paid options like Vellum (macOS only) or Affinity Publisher offer more design flair, but at a cost. For free alternatives, nothing matches Sigil's depth for direct EPUB work.
Final Verdict: 9/10
In 2026, Sigil remains my go-to for EPUB editing. It's reliable, powerful, and costs nothing. If you're serious about self-publishing or need clean ebooks without vendor lock-in, download it from the official GitHub repo and give it a try. Pair it with Calibre for conversions, and you've got a pro-level workflow for free.
Highly recommended for anyone who wants control over their ebooks!