<span class="mw-page-title-namespace">Template</span><span class="mw-page-title-separator">:</span><span class="mw-page-title-main">CustomHeader</span>
Fabrice P. Lauss𝕪s hun Web

Replaces the header picture at the top of the page with one of your own, and lays a title and a blurb over it. The skin does the moving (a few lines in skin.mustache); this template only says what to move and where to put it.

{{CustomHeader
|image=Roof-of-Faro.jpg
|title=Trip to the Algarve (May 2017)
|blurb=The ''Algarve'', from Arabic al-Gharb, «the West»...
|titlestyle=top:5px;left:10px;font-size:32px;color:white;background-color:rgba(54, 25, 25, 0.5)
|blurbstyle=bottom:20px;right:20px;font-size:large;width:66%;text-align:right;color:white;background-color:rgba(54, 25, 25, 0.5)}}
Parameter Meaning
image the name of an uploaded file — Roof-of-Faro.jpg, or File:Roof-of-Faro.jpg, whichever you have in hand. Not a URL: the address is worked out by the wiki that is rendering the page, so the same name finds the picture here and on laussy.org. A full URL is still accepted, for a picture that lives somewhere else, but then it is your business to make sure it resolves in both places.
title the large text over the picture. Plain wikitext.
blurb the paragraph over the picture. Plain wikitext too, so ''italics'', [[links]] and templates all work as they do anywhere else.
titlestyle, blurbstyle CSS for the two boxes, written as CSS. top:/bottom: and left:/right: place them against the corners of the picture; color:, background-color:, font-size:, width:, text-align: do the rest. Anything CSS understands is allowed, in any order.

Everything is optional. With no image the usual header picture stays; with no title or blurb that box is simply not drawn.

Notes

A blurb cannot contain a |, which the parser reads as the start of the next parameter — write &#124; or wrap it in <nowiki>.

If the file named cannot be found, the address is left as written and the skin falls back to the standard header picture — so a typo costs you the banner, not the page.

The banner is 780 pixels wide on the page, so a photograph is served at 1560 — two screen pixels to each of those, which is what a good display asks for — rather than at whatever the camera produced. Upload the full-size picture and forget about it: the file as uploaded is used when it is already narrower than that, and it is never enlarged. PNG, GIF and SVG are handed over untouched, whatever their size: MediaWiki re-encodes a resized PNG larger than the original as often as not (both MULTIPHOTONICS banners grew by a third when tried), a resized GIF loses its animation, and an SVG is not a grid of pixels in the first place.

The older parameter names still work and need not be changed: headertext for title, and headercolor + headercolorbackground + headerposition (and the blurb… three) for the two style parameters. Giving titlestyle or blurbstyle overrides its three.