Open Sans

by Steve Matteson ★★★★★ Sans-serif Variable Font
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Quick Answer

Open Sans is a variable sans-serif font with 2 adjustable axes (Weight, Width). Humanist sans-serif with excellent legibility. One of the most popular fonts on the web.

Performance Impact

93%
Size Reduction
200 KB → 14 KB
-380ms
LCP Improvement
Core Web Vitals boost
11ms
4G Transfer Time
After optimization
100ms
Max Render Block
With font-display: swap

Download Time by Network

Slow 3G (400 Kbps) 280ms
vs ~4000ms unoptimized
Fast 3G (1.5 Mbps) 75ms
vs ~1067ms unoptimized
4G LTE (10 Mbps) 11ms
vs ~160ms unoptimized

Optimization reduces Open Sans from 200 KB to 14 KB — making your site faster on every device.

Try Open Sans

Live Preview

Variable Axes
400
300 800
100%
75 100
Loading Open Sans...
Quick samples:

Variable Axes

Open Sans includes 2 variable axes, giving you fine-grained control over the font's appearance.

wght

Weight

Controls weight from Light (300) to ExtraBold (800)

Range: 300 – 800 (default: 400)
wdth

Width

Controls width from Condensed (75) to Normal (100)

Range: 75 – 100 (default: 100)

How to Optimize Open Sans

1

Subset to Latin

Remove Cyrillic, Greek, Hebrew, and Vietnamese if not needed.

Savings: 65-75%

2

Convert to WOFF2

WOFF2 offers the best compression for web delivery.

Savings: 30-40%

3

Use variable font

One variable font file replaces multiple static weight files.

Savings: 40-60%

4

Use font-display: swap

Prevent invisible text during loading.

Savings: Performance

File Size Comparison

Open Sans Variable (full)
~200 KB
All weights, all scripts
Open Sans Variable (Latin)
~55 KB
Latin subset only
Open Sans Regular WOFF2
~18 KB
Single weight, Latin
Optimized with Sift
~14 KB
Subset + WOFF2 + optimized

Sift optimizes your fonts for maximum performance with 90%+ size reduction

CSS Implementation

CSS
@font-face {
  font-family: 'Open Sans';
  src: url('/open-sans.woff2') format('woff2');
  font-display: swap;
  font-weight: 300 800;
}

body {
  font-family: 'Open Sans', sans-serif;
}

For variable fonts, you can use font-variation-settings to control axes:

.custom-weight {
  font-variation-settings: "wght" 400, "wdth" 100;
}

Pro Tips for Open Sans

💡

Great for body text

Open Sans excels at body copy due to its high x-height and open letterforms.

💡

Pair with a display font

Combine with Playfair Display or Montserrat for headings.

💡

Use Condensed for tight spaces

The variable font includes condensed widths for navigation and labels.

💡

Skip italics if possible

Open Sans italics are rarely needed. Save bytes by excluding them.

Frequently Asked Questions

What is Open Sans?
Open Sans was designed by Steve Matteson and commissioned by Google. It's a humanist sans-serif with open forms and a neutral yet friendly appearance. The letterforms have been optimized for print, web, and mobile interfaces, making it one of the most versatile fonts available.
Is Open Sans a variable font?
Yes, Open Sans is a variable font with 2 axes: Weight, Width. This means you can continuously adjust properties for precise control.
How do I optimize Open Sans for web?
To optimize Open Sans: 1) Convert to WOFF2 format for smaller files, 2) Subset to only the characters you need, 3) Use font-display: swap to prevent invisible text, 4) Preload critical font files. Sift can automate this entire process.
What license does Open Sans use?
Open Sans uses the SIL Open Font License 1.1 license.

Optimize Open Sans Now

Convert to WOFF2, subset to Latin, and add font-display: swap in seconds.

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