The RevisionSlider

September 18, 2016 0 By addshore

The RevisionSlider is an extension for MediaWiki that has just been deployed on all Wikipedias and other Wikimedia websites as a beta feature. The extension was developed by Wikimedia Germany as part of their focus on technical wishes of the German speaking Wikimedia community. This post will look at the RevisionSliders design, development and use so far.

What is the RevisionSlider

Once enabled, the slider appears on the diff comparison page of MediaWiki, where it aims to enable users to more easily find the revision of a page that introduced or removed some text as well as making the navigation of the history of the page easier. Each revision is represented by a vertical bar extending upward from the centre of the slider for revisions that added content and downward from the slider for those that removed content. Two coloured pointers are used to indicate the revisions that are currently being compared, the colour coding matches the colour of the revision changes in the diff view. Each pointer can be moved by dragging to a new revision bar or by clicking on the bar, at this point the diff will be reloaded using ajax for the user to review. For pages with many revisions arrows are enabled at the ends of the slider to move back and forward through revisions. Extra information about the revisions represented by bars is shown in a tooltip on hover.

Deployment & Usage

The RevisionSlider was deployed in stages, first to test sites in mid July 2016, then to the German Wikipedia and a few other sites that have been proactive in requesting the feature in late July 2016, and finally to all Wikimedia sites on 6 September 2016. In the 5 days following the deployment to all sites the number of users using the feature increased from 1739 to 3721 (over double) according to the Grafana dashboard This means the beta feature now has more users than the “Flow on user talk page” feature and will soon overtake the number of users with ORES enabled unless we see a sudden slow down

The wish

The wish that resulted in the creation of the RevisionSlider was wish #15 from the 2015 German Community Technical Wishlist and the Phabricator task can be found at The wish actually reads (roughly translated) When viewing the diff a section of the version history, especially the editing comments show be show. Lots of discussion follows to establish the actual issue that the community was having with the diff page, and the consensus was it was generally very hard to move from one diff to another. The standard process within MediaWiki requires the user to start from the history page to select a diff. The diff then allows moving forward or backward revision by revision but big jumps are not possible without first navigating back to the history page.

The first test version of the slider was inspired by the user script called RevisionJumper. This script provided a drop down menu in the diff view that provided various options to jump to a version of the page considerably before or after the current shown version. This can be seen in the German example below.

DerHexer (, „Gadget-revisionjumper11 de“,

DerHexer (, „Gadget-revisionjumper11 de“,

The WMF Communit Tech team worked on a prototype during autumn 2015 which was then picked up by WMDE at the Wikimedia Jerusalem hackathon in 2016 and pushed to fruition.

DannyH (WMF) (, „Revslider screenshot“,

DannyH (WMF) (, „Revslider screenshot“,

Further development