Peter Müller
Dad, Cancer survivor, web tooling radical. @Assetgraph maintainer, Mochajs core member, Open source enthusiast and public speaker
High performance
web fonts
Image Source: Formula 1
~70%
use web fonts
User Experience
Hello World!
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Hello World</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<h1>Hello World!</h1>
</body>
</html>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Hello World</title>
<link rel="stylesheet"
href="https://fonts.googleapis.com/css?family=Tangerine:700">
<link rel="stylesheet" href="style.css">
</head>
<body>
<h1>Hello World!</h1>
</body>
</html>
System Fonts vs Google Fonts
A user experience
Why SO SLOW?
Image Source: MC Drei-Finger-Faultier
Moto 4G, slow 3G connection (global average)
CSS loads are render blocking
Fonts only load when rendering
New connections are expensive
0.0s
4.1s
6.5s
Is it happening?
First paint
First meaningful paint
flash of Invisible text
Loading fonts faster
LOADING FONTS FASTER
Taking control
Image Source: Julius LeBlanc Stewart
Self-hosting Google Fonts
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Hello World</title>
<style>
@font-face {
font-family: 'Tangerine';
font-style: normal;
font-weight: 700;
src: url('fonts/tangerine-v9-latin-700.woff2') format('woff2'),
url('fonts/tangerine-v9-latin-700.woff') format('woff');
}
</style>
<link rel="stylesheet" href="style.css">
</head>
<body>
<h1>Hello World!</h1>
</body>
</html>
Preload
Image Source: Oversize Load
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<!-- Tell the browser to load this immediately: 68.19% global usage-->
<link rel="preload" as="font" type="font/woff2" crossorigin="anonymous"
href="fonts/tangerine-v9-latin-700.woff2">
<title>Hello World</title>
<style>
@font-face {
/* tangerine-700 - latin */
font-family: 'Tangerine';
font-style: normal;
font-weight: 700;
src: url('fonts/tangerine-v9-latin-700.woff2') format('woff2'), /* Chrome 26+, Opera 23+, Firefox 39+ */
url('fonts/tangerine-v9-latin-700.woff') format('woff'); /* Chrome 6+, Firefox 3.6+, IE 9+, Safari 5.1+ */
}
</style>
<link rel="stylesheet" href="style.css">
</head>
<body>
<h1>Hello World!</h1>
</body>
</html>
<style>
@font-face {
font-family: 'Tangerine';
font-style: normal;
font-weight: 700;
src: url('fonts/tangerine-v9-latin-700.woff2') format('woff2'),
url('fonts/tangerine-v9-latin-700.woff') format('woff');
}
</style>
<script>
/* 86.3% global usage support: https://caniuse.com/#feat=font-loading /*
try {
document.fonts.forEach(function(f) {
f.family.indexOf('Tangerine') !== -1 && f.load()
})
} catch (e) {}
</script>A Preload Polyfill
15%
EXTRA
subsetting
Image Source: Bram Stein
Google fonts subsetting
/* cyrillic */
@font-face {
font-family: 'Open Sans';
font-style: normal;
font-weight: 400;
src: local('Open Sans Regular'), local('OpenSans-Regular'), url(https://fonts.gstatic.com/s/opensans/v15/mem8YaGs126MiZpBA-UFUZ0bbck.woff2) format('woff2');
unicode-range: U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* greek */
@font-face {
font-family: 'Open Sans';
font-style: normal;
font-weight: 400;
src: local('Open Sans Regular'), local('OpenSans-Regular'), url(https://fonts.gstatic.com/s/opensans/v15/mem8YaGs126MiZpBA-UFVp0bbck.woff2) format('woff2');
unicode-range: U+0370-03FF;
}
/* latin */
@font-face {
font-family: 'Open Sans';
font-style: normal;
font-weight: 400;
src: local('Open Sans Regular'), local('OpenSans-Regular'), url(https://fonts.gstatic.com/s/opensans/v15/mem8YaGs126MiZpBA-UFVZ0b.woff2) format('woff2');
unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}Image Source: Aggressive young crocodile
Aggressive Subsetting
Image Source: Bram Stein
Graceful superset fallback
@font-face {
font-family: 'Tangerine';
src: url('fonts/tangerine-full.woff2') format('woff2');
}
@font-face {
font-family: 'Tangerine__subset';
src: url('fonts/tangerine-subset.woff2') format('woff2');
}
h1 {
font-family: 'Tangerine__subset', 'Tangerine', sans-serif;
}NEW!
Technique:
What characters am I using?
20%
OFF
Controlling rendering: font-display
High performance web fonts
Self-host Google Fonts
Create Font Subsets
Preload Subsets
CSS Font Loading API (Preload Fallback)
Graceful Superset Fallback
Font-display: swap
Could this all be automated?
Self-host Google Fonts
Create Font Subsets
Preload Subsets
CSS Font Loading API (Preload Fallback)
Graceful Superset Fallback
Font-display: swap
Introducing: Subfont
npx subfont hello-world-google-fonts.html -i --inline-css
Nearest competitor: System fonts!
Subfont 💖 jamstack
Image Source: Michal Osmenda
Subset caveat: Kerning
Subset caveat: ligatures
Controlling order: Font face observer
THANKS!
High Performance Web Fonts, CSS-Minsk-JS 2018
By Peter Müller
High Performance Web Fonts, CSS-Minsk-JS 2018
Web fonts and web performance are diametrical opposites. Your time to meaningful paint suffers from inefficient loading. Web fonts are also empowering your designers to improve legibility and keep brand consistency. Choose one: Performance or design? I'm here to tell you how you can have both
