The outline-offset property in CSS offsets a defined outline from an element's border edge by a specified amount. An outline, which is different from a border, does not take up any space on the page (like an absolutely positioned element) so the outline can be offset in any amount and it will not affect the position or layout of surrounding elements.
There is a non-standard way to stroke HTML text (SVG has a standard way). It's not particularly new. There are -webkit- and -moz- prefixes for it. Jen Simmons recently posted about it, with an example:
This CSS isn't fully-baked or fully-supported. But it's good enough to be used today, especially since it's simply offering a visual enhancement. It's not mission critical to making a website usable.
I'd only perhaps add that if you were going to do something like add a stroke around white text, you could wrap it in a @supports to be extra sure it'll be OK (just in case a browser exists that supports text-fill-color but not text-stroke-color) (more…)
Fonts on the web are essentially vector-based graphics. That's why you can display them at 12px or 120px and they remain crisp and relatively sharp-edged. Vector means that their shape is determined by points and mathematics to describe the shape, rather than actual pixel data. Because they are vector, it would make sense if we could do things that other vector programs (e.g. Adobe Illustrator) can do with vector text, like draw a stroke around the individual characters. Well, we can! At least in WebKit. Example:
Right away, I'm sure you are thinking: "Cool, but only WebKit supports, this, so if I set my text color to white and my background is white, the stroke makes it look cool in WebKit but disappears in other browsers!"
WebKit has your back on that one, you can set the text color with another proprietary property, so you're safe for all browsers:
h1 {
color: black;
-webkit-text-fill-color: white; /* Will override color (regardless of order) */
-webkit-text-stroke-width: 1px;
-webkit-text-stroke-color: black;
}
Shown here with @font-face font Anime Ace 2 by Nate Piekos:
Properly stroked!Fallback to solid color. Shown here in Firefox
Simulation
We can take this a bit further by not relying on the WebKit proprietary entirely. We can use the text-shadow property (supported in Firefox, Opera, and IE 10 as well) and simulate a stroke. We'll use four shadows, each 1px offset of black with no spread, one each to the top right, top left, bottom left, and bottom right. We'll use remove the WebKit proprietary -webkit-text-fill-color in favor of color since we're cross-browser compatible now. The only holdout would be IE9 and down, which of course you can use IE specific stylesheets to account for.
This is a stroke using all text-shadow. Pretty close to just as good as a real stroke. The primary issue is that you can only get 1px of stroke this way. Any more, and you see gaps. Any more with WebKit text stroke and there is issues too though, so it's kind of a horse apiece.
Combining
Using both a stroke and a shadow can be a great effect. Let's toss on a WebKit stroke, the all-around text-shadow stroke, as well as a deeper text-shadow stroke.
If you are familiar with Adobe Illustrator, you may know that you can align a stroke on the inside of a shape, outside, or centered. That option looks like this in the palette:
From left to right: center, inside, outside
For reasons unbeknownst to me, text in Illustrator can only be set to center stroke alignment as well. Once you expand the text into regular vector paths though, all three options become available. Reminder from Sam Frysteen: add a new stroke in the Appearance panel and move it below your text (basically mimics outside stroke alignment).
From top to bottom: inside, centered, outside.
Only outside text stroke alignment looks any good at all to me. It's unfortunate, both for CSS and for Illustrator, that the unchangeable default is centered. The solution is just not to go too crazy with the thickness of your stroke border and things should be OK. Note: the text-shadow-only solution doesn't have this problem, but also is unable to stroke any more than 1px.
If you use a pseudo element, you can stroke the same text behind the original text and kinda fake outside stroke.
We have a whole article on this alignment issue: Text Stroke: Stuck In The Middle With You. A minor bit of good news, the paint-order property allows you to esssentially have outside set strokes, once more browsers support it.
What we can't do
There are other things that vector based graphics programs can do with text. You can squish the letter horizontally / stretch them vertically. This type of text treatment is almost universally frowned upon, so no big loss that we can't do that. You can also set type on an irregular line (like around a circle). It certainly would be cool to do this with web text. Perhaps we could set text to follow the border path of its parent element.
p.circular {
width: 200px;
height: 200px;
border-radius: 100px;
/* NOT REAL */
text-align: border-path;
}
In Illustrator, we can also tell a stroke how to handle sharp corners: rounded, beveled, or mitered. These can have nice effects, are not possible on the web. However, the WebKit handling of corners is pretty nice at its default (whatever it is), and arguably nicer than any of the options in Illustrator.
Fancies
For the record, you can use any type of color value for the color of WebKit stroke (hex, rgba, hsla, keyword). That means transparent strokes if you want them, which indeed to "stack" in that if strokes overlap each other (common) they will be darker.
As far as WebKit keyframe animation, the stroke color will animate but the stroke width will not.
/* Only the color will change, not the width */
@-webkit-keyframes colorchange {
0% {
-webkit-text-stroke: 10px red;
}
100% {
-webkit-text-stroke: 20px green;
}
}
