font inspectorWhat font does Facebook use?
Facebook has long relied on system fonts for speed, adding Meta’s own typefaces for brand moments. We could only inspect the sign-in page, so this page lists the families but not a table of sizes.
Short answer: Facebook’s logged-out page uses the system font for most text, Meta’s Optimistic typeface for buttons and form labels, and Facebook Sans for the large tagline.
System font stack
System font74%- CSS name
Segoe UI Historic- Weights
- 400
- Sizes
- 15px
Optimistic
Self-hosted20.4%- CSS name
Optimistic- Weights
- 500, 600
- Sizes
- 17px · 15px
- Served from
- static.xx.fbcdn.net
Facebook Sans
Self-hosted5.6%- CSS name
Facebook Sans Normal- Weights
- 600
- Sizes
- 58.4px
- Served from
- static.xx.fbcdn.net
The font stack
The main font stack in the CSS:
font-family: "Segoe UI Historic", "Segoe UI", Helvetica, Arial, sans-serif;- Three different sources on one small page: the device’s own font, a corporate typeface and a brand typeface.
- The tagline measured 58.4px, a fractional size that points to fluid type.
Check any site yourself in one click.
Sites change their type without notice. Font Inspector shows the rendered font, size, weight and spacing of any text on facebook.com or anywhere else, and lists every font on the page. Free, no account.
About the fonts, and whether you can use them
System font stack
Facebook’s stack names system fonts. On our Windows machine it resolved to Segoe UI Historic. On Apple devices the same CSS shows San Francisco.
Can you use it? Free to use: name the system fonts in your CSS and each device supplies its own.
Optimistic
Meta’s corporate sans serif, shared across Facebook, Instagram and other Meta products.
Can you use it? Optimistic is proprietary to Meta. Figtree and Inter are free fonts with a similar clean, friendly tone.
Facebook Sans
Facebook’s brand typeface. It appears only in the large tagline.
Can you use it? Facebook Sans is proprietary and not available to license.
On Google Fonts: Figtree.
Finding a font does not license it. More in how to get a font you found, legally.
Get a similar look with a free font
This starter uses Figtree, which is open source, with the sizes and spacing measured above. It is an approximation, not a copy of Facebook’s brand typeface.
/* Approximates the Facebook look with a free font */
body {
font-family: "Figtree", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}
How we checked
We opened facebook.com in Chrome on September 21, 2026 and read the computed styles of its visible text: the declared font stack, the font actually rendered, and how much of the page’s text each family sets. That is the same data the Font Inspector extension shows under Fonts on this page. We re-check these pages periodically, and the date above shows the last inspection.
Facebook and its typefaces are trademarks of their respective owners. Font Inspector is not affiliated with Facebook.
Questions & answers
What font does Facebook use on its website?
Facebook’s logged-out page uses the system font for most text, Meta’s Optimistic typeface for buttons and form labels, and Facebook Sans for the large tagline.
Can I use the Facebook font?
Free to use: name the system fonts in your CSS and each device supplies its own.
How can I check what font Facebook uses myself?
Open facebook.com, then click any text with the Font Inspector extension, or right-click, choose Inspect and look at Rendered Fonts in the Computed tab. Sites change their typography, so checking the live page is the only way to be sure.