InstantCommons
InstantCommons is a feature of MediaWiki to allow the usage of any uploaded media file from the Wikimedia Commons in any MediaWiki installation world-wide.
Rationale
As of November 2023, Wikimedia Commons, the central media repository hosted by the Wikimedia Foundation, contains over 100 million files. Each of these files is available under a free content license or in the public domain; there are no other restrictions of use beyond those relating to use of official insignia or trademarks. Licenses which limit commercial use are considered non-free.
As awareness of the Commons grows, so does the desire of external parties to use content included therein, and to contribute new material. It is currently technically possible to load images directly from Wikimedia's servers in the context of any webpage. Such hotlinking is allowed, but it is problematic for multiple reasons:
- It does not respect the license terms of the image, and does not allow for other metadata to be reliably transported
- Besides failing to properly credit the author of the media file, it also does not give credit to Wikimedia
- It consumes Wikimedia bandwidth on every pageview (unless the image has been cached on the client side or through a proxy; this functionality is currently disabled by default)
- It does not facilitate useful image operations such as thumbnail generation and captioning and is difficult to use in the context of a wiki, particularly for standard layout operations
- It is tied to URLs as resource identifiers, which complicates mirroring
- It creates an untrackable external usage web, where any change on Wikimedia's side necessarily affects these external users
- It does not permit offline viewing, which is crucial in countries which have only intermittent network access.
InstantCommons seeks to address all this by providing an easy method for (cached) loading of images and metadata from Wikimedia's servers. Although caching functionality is part of the objective, it has been disabled since MediaWiki 1.27.2/1.28.1. InstantCommons was first implemented within MediaWiki, allowing for all MediaWiki image operations (thumbnailing, captioning, galleries, etc.) to be performed transparently. Other wiki engines can implement InstantCommons-like functionality using the API operations described below.
Basic feature set
During the installation, the site administrator can choose whether to enable InstantCommons. Ideally, however, the feature should be enabled by default (provided a writable upload directory is specified) to allow the largest possible number of users to use Wikimedia Commons content.
If the feature is enabled, the wiki behaves like a Wikimedia project, that is, if an image or other media file is referred to which exists on Commons, it can be included in a wiki page like a locally uploaded file by specifying its name. Local filenames take precedence over Commons filenames.
Configuration
Default method: $wgUseInstantCommons
For enabling InstantCommons in MediaWiki version 1.16 or later, it is sufficient to add this line to your LocalSettings.php (see $wgUseInstantCommons for details):
$wgUseInstantCommons = true;
Classic InstantCommons with local thumb caching
Default InstantCommons as enabled through $wgUseInstantCommons uses thumb images hotlinked from Wikimedia.[1]
This may be slow and may also interfere with file caching (broken links).
If you would like to generate and use thumbs on your local server, do not use $wgUseInstantCommons.
Instead, insert this code into LocalSettings.php as described here: Manual:$wgForeignFileRepos#Usage.
$wgForeignFileRepos[] = [
'class' => ForeignAPIRepo::class,
'name' => 'commonswiki', // Must be a distinct name
'apibase' => 'https://commons.wikimedia.org/w/api.php',
'hashLevels' => 2,
'fetchDescription' => true, // Optional
'descriptionCacheExpiry' => 43200, // 12 hours, optional (values are seconds)
'apiThumbCacheExpiry' => 86400, // 24 hours, optional, but required for local thumb caching
];
Using files via InstantCommons
With InstantCommons enabled, you can choose any image from Wikimedia Commons (e.g. this one), click the "Use this file" button (the button with the wiki icon 
next to) and paste the markup in your wiki.
In our example, pasting
[[File:Wikipedia-Marker-commons.svg|thumb|A picture from Wikimedia Commons embedded in this Wiki]]
will render the thumbnail (as can be seen on the right side of this page).
Note that when using files in this way you will still need to respect any licensing and other file use legal requirements - see Commons:Reusing content outside Wikimedia.
Troubleshooting
Set custom user agent
Since 2025, Wikimedia Commons may categorize your wiki as an unidentified origin and throttle or block its requests. This is due to enforcement of the Wikimedia Foundation User-Agent Policy, to mitigate the increase of automated scraping.
Unfortunately, the User-Agent used by InstantCommons did not set any origin. This will be fixed in MediaWiki 1.45 (including MediaWiki 1.39.14+, 1.43.4+, and 1.44.1+). If you encounter a throttling or block message when using InstantCommons, please add the below code snippet to the end of your LocalSettings.php file. This snippet is compatible with MediaWiki 1.34 and later:
$wgUseInstantCommons = false;
$wgForeignFileRepos[] = [
'class' => ForeignAPIRepoWithFixedUA::class,
'name' => 'wikimediacommons',
'apibase' => 'https://commons.wikimedia.org/w/api.php',
'url' => 'https://upload.wikimedia.org/wikipedia/commons',
'thumbUrl' => 'https://upload.wikimedia.org/wikipedia/commons/thumb',
'directory' => $wgUploadDirectory,
'hashLevels' => 2,
'transformVia404' => true,
'fetchDescription' => true,
'descriptionCacheExpiry' => 43200,
'apiThumbCacheExpiry' => 0,
];
class ForeignAPIRepoWithFixedUA extends \ForeignAPIRepo {
public static function getUserAgent() {
global $wgCanonicalServer;
$mediaWikiVersion = 'MediaWiki/' . MW_VERSION;
return "$mediaWikiVersion ($wgCanonicalServer) ForeignAPIRepo/T400881";
}
}
HTTPS
Since June 2015, Wikimedia Commons can only be accessed using HTTPS. Some installs may be missing their root certificate store which prevents MediaWiki from contacting Commons over HTTPS. If InstantCommons stopped working, try:
- Installing the php curl extension. (It is generally more reliable, and more likely to have proper certificates already installed.) On Debian/Ubuntu:
sudo apt-get install php-curl - Verifying you have an up-to-date certificate store. If you have the php curl extension installed, follow the instructions webaware or Talk:InstantCommons#Stop_working.
- Make sure the PHP function
curl_exec()is not disabled in your web server.
SElinux
If your server OS implements SElinux, please take a look at the dedicated section on the SELinux settings page, and make sure HTTPD scripts and modules can access the network successfully. If SElinux prevents HTTPD scripts and modules from connecting to WikiMedia Commons repository, the InstantCommons feature will simply not work.
Behind a firewall
If the server on which the wiki runs is behind a firewall, the wiki server must be granted outgoing http/https requests to commons.wikimedia.org and upload.wikimedia.org, for Instant Commons to work. The IP address ranges are found at wikitech:IP addresses.
If you need to use a proxy to access the internet from behind the firewall, see $wgHTTPProxy.
See also
- Manual:$wgForeignFileRepos – for the same functionality as InstantCommons but with other wikis
- PhotoCommons – WordPress plug-in to provide the same functionality
- Examples of sites which are using InstantCommons
- Extension:QuickInstantCommons
References
