sigplus Image Gallery Plus


sigplus Image Gallery Plus or (sigplus in short) is a straightforward way to add image galleries to an article with a simple syntax. The galleries exhibit the well-known lightbox effect: when a thumbnail is clicked, the corresponding image appears in a pop-up window overlay, without navigating away from the current page.

The plug-in implements features that are usually found only in image gallery Joomla plug-ins that are either commercial or require paid club membership. sigplus ships with all features included, there is no upgrade to a commercial professional version.

sigplus 1.5.x is out

In order to get access to the latest features, new sites should install sigplus 1.5.x or later. This page and related documentation is preserved for historical reasons; sigplus 1.4.x is no longer actively maintained or supported.


  • user-selectable pop-up window engine, including popular Slimbox, prettyPhoto, FancyBox and boxplus (specifically designed for sigplus)
  • user-selectable image slider/carousel/rotator
  • free-flow and grid layout mode; row, column and grid arrangement
  • support for image types .jpg, .png and .gif (with and without transparency)
  • best-fit thumbnail generation with automatic cropping and centering
  • progressive load feature to save network bandwidth [≥1.3]: only those images are fetched from the server that are being shown
  • multiple galleries per content item and per page
  • multilingual, search engine-friendly image labels and more verbose description set globally and for each individual image
  • right-to-left language support
  • download option to save high-resolution image version
  • image metadata processing; IPTC data extraction
  • custom styling (preview image margin, border, padding and opacity, slide duration and animation delay)
  • custom sort criteria (user-defined, file name, last modification time and random order)
  • large gallery support (100 or more images in a single gallery) [≥1.3]
  • 100% CSS and JavaScript, valid XHTML 1.0 and 1.1, passes WCAG v2 AAA automatic validation (when using labels file)
  • default global settings for the entire site and local parameter overrides for individual galleries
  • restricted-access galleries and more...


  • PHP version 5.1 or later
    How to check: open Help/System Info in administration back-end, look for PHP Version in column Setting.
  • GD or ImageMagick library support
    How to check: open Help/System Info in administration back-end, click tab PHP Information, find section gd, look for enabled next to features GD Support, GIF Read Support, GIF Create Support, JPG Support and PNG Support; or find section imagick and look for enabled next to imagick module.
  • JSON support (some advanced features only)
    Required only if you would like to pass engine-specific parameters to pop-up window, slider or overlay captions engines, e.g. {gallery slider:effect=shutter}fruit{/gallery}. Not required for passing regular parameters, e.g. {gallery lightbox=boxplus rows=2 cols=4}fruit{/gallery}.
    How to check: open Help/System Info in administration back-end, click tab PHP Information, find section json, look for enabled next to feature json support and check whether you have at least 1.2.0 of json.

Documentation and demo

A comprehensive documentation covers simple usage syntax of how to include an image gallery in your articles (content items) and add image labels, as well as more advanced topics such as custom styling or inline parameter overrides. Usage is demonstrated by examples that show what the output looks like in each case. If you encounter errors, make sure to read the list of frequently asked questions before you contact the developer.


sigplus Image Gallery Plus is available for download under GNU/GPL at BitBucket. There are two separate extensions:

  • The sigplus plug-in (plg_sigplus) contains all necessary files for sigplus to be fully operational. Once plg_sigplus has been installed and enabled, you can use the plug-in by typing the gallery activation tag in a content item.
  • The sigplus module (mod_sigplus) is a supplement to the sigplus plug-in that allows you to have a sigplus gallery in a module position without using the activation tag. It requires plg_sigplus to be installed, or it will trigger an error message otherwise.

Beta version and “nightly builds”

Should you wish to experiment with the upcoming features, you can download the latest beta version or “nightly build” (the latest snapshot of sigplus development) of plg_sigplus and mod_sigplus. The beta version is not intended for a production environment, however, you are encouraged to evaluate it and This email address is being protected from spambots. You need JavaScript enabled to view it. you might encounter. (A beta version or “nightly build” might not be available if the latest verision of the software has just been released to the general public.)


It takes time and effort to develop and maintain sigplus. Especially if you use the extension in a commercial environment, you are strongly encouraged to make a donation even though you are not obliged to.

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