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diff
(short for difference) displays the changes between two revisions of a page.
Diffs are a fundamental component of navigation and content moderation on MediaWiki wikis.
The platforms in the wiki ecosystem have several versions of a diff depending on which device and installation of MediaWiki is being used.
When and why to use a diff?
The main reason to use a diff is to review a specific change to a page made by yourself or someone else.
There are many possible reasons to do this:
To help find instances of vandalism
To determine when a section, sentence, or word was added or removed
To determine which editor made a given change
As a starting point to further actions as the diff contains
edit
undo
, and other actions as well as links to the editor's user and talk pages.
How to navigate to view a diff?
The most common way to view a diff is through the "
Revision history
".
This is accessible via the
View history
tab.
From there, you can use
prev
to view diffs of single revisions, or use the radio buttons and the
Compare selected revisions
button to view diffs across multiple revisions.
Most
special pages
that list changes will usually include links to diffs, such as:
Another way to view a diff is with the
Special:Diff
page.
To use this, you must know the IDs of the revisions you want to compare.
Revision IDs can be retrieved by looking at the
diff=123
portion of a diff URL, where
123
is the diff ID.
Additionally, you can use the value of the
oldid
parameter to get the diff of that revision against the previous one.
Components to a diff
Below is a visual representation of the important components of a diff page which you will see when viewing the difference between two versions.
Components of a diff
This interactive example shows the top of the diff page (some of the links are dummy links).
The older revision is shown on the left, the newer revision on the right.
Line 8:
Line 8:
For sysops and those with the rollback flag, a revert button is shown allowing them to revert from the new version to the old one.
For sysops and those with the rollback flag, a revert button is shown allowing them to revert from the new version to the old one.
This is only shown when viewing the diff between the
current
version and the one
immediately preceding it
This is only shown when viewing the diff between the
recent
version
of a page
and
the last version by an author other than
the one
of the most current version
This example shows the top of the diff page, with the links described above.
This example shows the top of the diff page, with the links described above.
Line 25:
Line 25:


[[MediaWiki User's Guide]]
Unchanged text
Unchanged text is dark grey on light grey (only parts before and after changed text are shown).
Colour key
Previous diff
Newer diff
Unchanged
Unchanged
Moved text
Identical text that has moved from one place to another is usually represented as added and removed text.
On MediaWiki installations using
Wikidiff2
, there may be an arrow icon more clearly indicating where the moved text went to.
Added text
Lines containing added text have a plus icon (
) before them.
The added words and characters are highlighted and in bold.
Removed text
Lines containing removed text have a minus icon (
) before them.
The removed words and characters are highlighted and in bold.
Replaced text
We can see what has been replaced with new content when there's a + icon and a − icon next to the phrase where the change happened.
Paragraphs which have changed are black on white, with an orange border on the old revision side and a blue border on the new version side.
Inserted and removed text is highlighted with the border color and in bold.
Where whole paragraphs have been removed or inserted, no highlighting or bolding is applied and the other side is blank.
Colour key
Old revision
New revision
Paragraph changed
Paragraph changed
Colour key
Old revision
New revision
Paragraph removed
Paragraph added
Colour key
Old revision
New revision
Removed characters
Added characters
Linking to a diff
Diffs can be linked to by copying the URL while viewing the diff — this URL has two parameters,
diff
and
oldid
Linking to a diff from outside a wiki can be done by using the full URL, for example:
The diff
special page
at
Special:Diff
makes it easier to create shorter URLs which redirect to diffs.
From within a wiki, these links can take the following forms:
These links may be used in the
edit summary
as well as being adapted like any other internal links, e.g.
[[Special:Diff/1242286/1242287|see this diff]]
see this diff
For example, the full URL
[https://mediawiki.org/w/index.php?diff=1242287 1242287]
could also be written as
[[Special:Diff/1242287|1242287]]
By default, the later revision of the page is displayed in full below the diff — this can be turned off via a
preference
Don't show page content below diffs
) or by setting
diffonly=1
in the URL.
Links to diffs without the page text can be created:
Inline diffs
MediaWiki version:
1.35
Since MediaWiki 1.35, an inline diff (also known as a
unified diff
) is available.
As of 2022 this is only available with the
wikidiff2
engine.
Inline diffs can be accessed by passing the
diff-type=inline
parameter in the URL (
example
).
MediaWiki version:
1.41
As of MediaWiki 1.41, a toggle was added to diff pages that allows users to switch between inline and two-column in the user interface.
T336716
Content added
Content deleted
For sysops and those with the rollback flag, a revert button is shown allowing them to revert from the new version to the old one.
This is only shown when viewing the diff between the
current
version and the one
of a page and the last version by an author other than the one of the most current version.
This example shows the top of the diff page, with the links described above.

[[MediaWiki User's Guide]]
↲ newline
The following changes were introduced for inline diff:
Legends and tooltips that explain the blue and yellow highlights. (
T324759
Annotation that represent when one or more lines are added or deleted. (
T330247
How to report bugs?
Bugs should be
reported on Phabricator
under the
#MediaWiki-Page-diffs
tag.
User Preferences
The following user
preferences
are available in the
Diffs
section of the
Appearance
preferences tab:
Don't show page content below diffs
Toggle the display of the page text below the diff. This text is the later of the two revisions of the page.
Don't show diff after performing a rollback
Whether to show the diff of the rolled back revision after a rollback.
Some extensions also add their own preferences related to diffs.
One such extension is
Extension:RevisionSlider
, which can be disabled in preferences using the
Don't show the revision slider
preference in that section.
See also
Help:History
– Navigating and understanding page history.
Visual diffs
– Diffs in the VisualEditor and VisualDiff extensions.