For the impatient, the installer files (and source) can be found as assets at the top of the Github Release page.

This Sigil release is a mix of bug fixes and new features for both epub2 and epub3 users. Some of the highlights for this release include:

Allow plugins to supply their own icon (plugin.png 48×48) for use on the Quick Launch Toolbar icons.

Allow users to add custom css rules to Preview/Book View by creating a file called “custom_preview_style.css” in the Sigil preferences folder.

The Sigil User Manual was updated to include the feature set consistent with Sigil v0.9.x. We have Tex2002ans to thank for this!

Many crashing scenarios were also addressed.

The specific changes/additions follow…

Bug Fixes

  • Fix signal handling to prevent double launch of plugins immediately after plugin installed
  • Fixed incorrect named entity tooltips for many of the Insert-> Special Characters
  • Fixed lack of recognition of woff2 fonts inside Sigil and for plugins
  • Fix segfault when .xml is first file in BookBrowser and add new html or split at cursor is invoked
  • Fix bug that allowed multiple audio/video tabs of the same resource to be opened
  • Fix plugin related bug when adding/removing last xhtml file
  • Fix Text Direction setting inside body to use structural dir attribute under epub3
  • Fix duplicate group-position property in epub3 MetaData Editor
  • Use absolute path references when first opening Sigil with an ebook so that Open Recent works better
  • Fix “issue” in handling self-closing script tags in head (similar issue that we had with self-closing title tags)
  • Fix issue converting Qt Strings to their Python equivalent when outside the BMP
  • Fix issue with trying to add existing html files when names clash due to case insensitive file systems
  • Fix crash bug after styling text in BookView and immediately going to CodeView without moving cursor
  • Fix crash bugs after deleting resources contained in a Report in the BookBrowser
  • Fix bug that destroys nav if left in unparseable state by user even temporarily
  • Fix bug that moved cursor to beginning of tag block when save is done in CodeView

New Features

  • allow plugins to supply their own icon (plugin.png 48×48) for use on the Quick Launch Toolbar icons
  • extend plugin interface to include the status of the epub inside Sigil (modified or saved)
  • extend plugin interface to include the path to the saved epub file or the null string if never saved
  • extend Insert->Special Characters to include both a Greek letter panel and a mathematical symbol panel
  • add support for calibre:series and calibre:series_index to Metadata Editor for epub2
  • add support for calibre:title_sort to Metadata Editor for epub2
  • add support for clicking internal links in Preview to load the proper destination tab
  • add support for loading Qt’s base translation files if present. Allows buttons on native qt dialogs to
    be translated (Windows users may need to manually copy newer qtbase_xx.qm files to Sigil’s translation
    directory if they didn’t exist in Qt5.6.2)
  • allow user to add custom css rules to Preview/Book View by creating a file called “custom_preview_style.css”
    in the Sigil preferences folder (not responsible for custom css and ebook css fighting with each other)

Be aware that Sigil-0.9.10 still enforces the need for epub3 to have and support an NCX so that it generates as backward a compatible epub as possible. This may be relaxed in future releases.

Sigil-0.9.10 like its predecessors passed all of the following tests for epub3 support: iframe, img, audio, video , mathml, svg (except for svg support in the spine), javascript, and of course recognizing and allowing html5 specific tags like section, and etc. Sigil-0.9.10 also supports javascript based local-storage and display of embedded pdfs.

Download Location
The official location for downloading this Sigil release (and all official releases) is:

The latest version of the Sigil User Guide can be downloaded from:

Downloading binaries from anyplace else is simply NOT a good idea as they could inject anything into their own downloads. After downloading, please verify the downloaded binary exactly matches what was originally posted by running an SHA 256 checksum on the file before installing it. See the file Sigil-0.9.10-CHECKSUMS.sha256.txt for the correct checksums for each file and instructions for how to calculate a SHA 256 Checksum for your download. The Mac OS X Package has also been code signed with my Apple Developer signature.

Windows Users
If your current version of Sigil is 0.9.6 or earlier, it’s recommended (but not required) that you uninstall that version before installing 0.9.10. Some compiled Python files have had their file extentions changed (as well as the change to Python 3.5). As a result, there will be a lot of extraneous files left lying around if you just install the new over the old. It won’t cause any functionality problems, but if disk space is at a premium, you may want to clean things up a bit. You can do this by uninstalling Sigil at any time (even after 0.9.10 is installed) and reinstalling. Doing so won’t affect your any of your preferences, plugins, keyboard shortcuts, clips, saved searches, etc.

Linux Users
There are currently no official binary releases available for Linux on the Sigil Release page. Please check with your favorite distro’s software repositories to see if they have Sigil for installation via your OS’s package management system. If not, there are build instructions for compiling Sigil yourself in the source archive’s docs directory:

Don’t forget the FlightCrew plugin
Please note, the epub2 validator FlightCrew has been converted to a plugin for Sigil 0.8.900 and later.
This plugin has been updated for Sigil-0.9.3 (and later). It can be downloaded from the official Sigil-Ebook flightcrew repository if you have not already installed it.

Attention Mac OS X Users
Per the recommendation of (see, due to bugs and the age of Apple’s internal Tcl library, you should also download and install ActiveState’s ActiveTcl Community Edition. To get the latest bug fixes, Sigil-0.9.10’s embedded Python has been linked with the very latest version: Tcl

We may not redistribute this Package with Sigil due to ActiveState’s binary non-redistribution policy.

So please, if you have not already done so download and install this version of ActiveState’s Active Tcl Community Edition, until we get a chance to do our own build of Tcl from source for future releases. ActiveState is a primary contributor to and a respected and trusted source for python and tcl/tk related binaries on both Windows and Mac OS X.


Signed Source Archives and Git Tags
Starting with Sigil v0.9.9, the Git tags and source archives used for Sigil releases are signed with Doug Massay’s PGP Key. His public key can be found and retrieved from any public key server. The fingerprint for his public key is: B5A5 6206 AB0F BC1A 24EF AB8A A166 D29A 8FCD AC63

Some Additional things

When you fire up Sigil for the very first time:

  • navigate to the new General Preferences and select the default
    epub version you plan to work with (epub 2 or epub3) so that new
    empty ebooks start with the correct code.
  • if you plan to work with epub3 epubs, you should change your
    PreserveEntities setting to use ONLY NUMERIC entities.
    For example use & # 1 6 0 ; for non-breaking spaces and etc.
  • We strongly recommend enabling Mend On Open in your settings
    for best performance with Sigil.