How to use Apple's new San Francisco font on a webpage

Apple's new system font is not publicly exposed. Apple has started abstracting system font names:

The motivation for this abstraction is so the operating system can make better choices on which face to use at a given weight. Apple is also working on font features, such as selectable “6″ and “9″ glyphs or non-monospaced numbers. It’s my guess that they’d like to bring these features to the web, as well.

Safari and Firefox use SF for -apple-system; Chrome recognizes BlinkMacSystemFont:

body {
    font-family: -apple-system, BlinkMacSystemFont, sans-serif;
}

There are also other variations:

font-family: -apple-system-body
font-family: -apple-system-headline
font-family: -apple-system-subheadline
font-family: -apple-system-caption1
font-family: -apple-system-caption2
font-family: -apple-system-footnote
font-family: -apple-system-short-body
font-family: -apple-system-short-headline
font-family: -apple-system-short-subheadline
font-family: -apple-system-short-caption1
font-family: -apple-system-short-footnote
font-family: -apple-system-tall-body

You can demo these at the following fiddle; most are not supported yet: http://jsfiddle.net/v94gw9nx/

I got my info from Craig Hockenberry's article which has a lot of great info about using the font: http://furbo.org/2015/07/09/i-left-my-system-fonts-in-san-francisco/

Also, some great info on the Surfin' Safari blog about using abstracted system fonts: https://www.webkit.org/blog/3709/using-the-system-font-in-web-content/

And apparently Apple is working with the W3C to standardize using a generic "system" font name in CSS. https://lists.w3.org/Archives/Public/www-style/2015Jul/0169.html

Download the SF font .otf files for your own personal use: https://developer.apple.com/fonts/

None of the current answers including the accepted one will use Apple's San Francisco font on systems that don't have it installed as the system font. Since the question isn't "how do I use the OS X system font on a webpage" the correct solution is to use web fonts:

@font-face {
  font-family: "San Francisco";
  font-weight: 400;
  src: url("https://applesocial.s3.amazonaws.com/assets/styles/fonts/sanfrancisco/sanfranciscodisplay-regular-webfont.woff");
}

Source

Last time tested: March 2018

To address the question

How to use Apple's new San Francisco font on a webpage

font-family: -apple-system, system-ui, BlinkMacSystemFont;

or (even shorter):

font-family: -apple-system, BlinkMacSystemFont;

should suffice.

If you want to default to system font on multiple platforms, though, I'd suggest:

font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu;

• -apple-system — San Francisco in Safari (on Mac OS X and iOS); Neue Helvetica and Lucida Grande on older versions of Mac OS X.
• system-ui — default UI font on a given platform.
• BlinkMacSystemFont — equivalent of -apple-system, for Chrome on Mac OS X.
• "Segoe UI" — Windows (Vista+) and Windows Phone.
• Roboto — Android (Ice Cream Sandwich (4.0)+) and Chrome OS.
• Ubuntu — all versions of Ubuntu.

The idea is borrowed from the following issue on github.

You can look up fonts for other OS or older versions of them in this article on css-tricks.

-apple-system allows you to pick San Francisco in Safari. BlinkMacSystemFont is the corresponding alternative for Chrome.

font-family: -apple-system, BlinkMacSystemFont, sans-serif;

Roboto or Helvetica Neue could be inserted as fallbacks even before sans-serif.

https://www.smashingmagazine.com/2015/11/using-system-ui-fonts-practical-guide/#details-of-approach-a (how or previously http://furbo.org/2015/07/09/i-left-my-system-fonts-in-san-francisco/ do a great job explaining the details.