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The typefaces Y Combinator companies use

Keifont opened the website of every active company in the Y Combinator directory and recorded the typefaces each homepage rendered. 3,797 websites loaded and are counted here. Parked domains, bot checks and error pages are left out.

  • Inter is on 28.8% of them, 1,095 websites.
  • The 10 most used typefaces appear on 55.5% of the websites.
  • Of the 3,559 websites where Keifont found at least one typeface, 54.5% use only typefaces from the Google Fonts library.
  • 8.4% set their body text in a font the visitor's device already has, such as system-ui, Helvetica or Arial.

Compare Inter and Geist, the two most used, in the tool

Most used

Share of the 3,797 websites that render the typeface anywhere on the homepage
RankTypefaceWebsites ShareSource
1Inter1,09528.8%Google Fonts
2Geist3358.8%Google Fonts
3Geist Mono2636.9%Google Fonts
4JetBrains Mono2175.7%Google Fonts
5DM Sans1844.8%Google Fonts
6Poppins1684.4%Google Fonts
7Manrope1353.6%Google Fonts
8IBM Plex Mono1313.5%Google Fonts
9Montserrat1102.9%Google Fonts
10Roboto1002.6%Google Fonts
11Instrument Serif962.5%Google Fonts
12Space Grotesk922.4%Google Fonts
13Plus Jakarta Sans912.4%Google Fonts
14Open Sans872.3%Google Fonts
15Instrument Sans822.2%Google Fonts
16Lato741.9%Google Fonts
17Satoshi701.8%Other
18Helvetica Neue661.7%Other
19IBM Plex Sans661.7%Google Fonts
20Outfit651.7%Google Fonts
21DM Mono621.6%Google Fonts
22Inter Tight591.6%Google Fonts
23Figtree531.4%Google Fonts
24Playfair Display511.3%Google Fonts
25Newsreader481.3%Google Fonts
26Fraunces441.2%Google Fonts
27Archivo431.1%Google Fonts
28Georgia391%Other
29SF Mono381%Other
30Source Serif 4381%Google Fonts

By batch

Batch yearsWebsites Three most usedOnly Google FontsBody text in a device font
2005-2019757Inter 18.6%, Poppins 5.9%, Open Sans 5.8%43.2%6.6%
2020-2022958Inter 27.6%, Poppins 8.6%, DM Sans 6.2%50.7%9.2%
2023-2024821Inter 35.9%, Geist 10.2%, Geist Mono 7.6%55.9%9.9%
2025-20261,253Inter 31.4%, Geist 16%, Geist Mono 12.6%63.3%7.8%

By industry

Industries with at least 60 websites, as the Y Combinator directory labels them
Industry WebsitesThree most used
B2B1,988Inter 32.6%, Geist 10.8%, Geist Mono 9.3%
Healthcare485Inter 21.4%, Poppins 8%, Geist 7%
Fintech386Inter 26.4%, Poppins 8.5%, DM Sans 8%
Consumer366Inter 27%, Poppins 4.4%, Geist 3.6%
Industrials359Inter 23.7%, JetBrains Mono 7.2%, Geist 7%
Real Estate and Construction88Inter 29.5%, Geist 10.2%, Figtree 5.7%
Education71Inter 22.5%, Poppins 7%, Geist 5.6%

Heading and body pairs

The most common combinations where the homepage's main heading and its body text use different typefaces.

HeadingBody text Websites
GeistGeist Mono54
InterJetBrains Mono43
InterGeist Mono16
DM SansInter10
SF Pro TextMenlo8
PoppinsInter8
GeistInter8
DM SansDM Mono7
InterIBM Plex Mono7
Instrument SerifGeist Mono7

Startups and design studios

The same measurement on 3,128 websites from Typewolf's index, which lists design-led company and studio sites.

Y Combinator companies

TypefaceShare of sites
Inter28.8%
Geist8.8%
Geist Mono6.9%
JetBrains Mono5.7%
DM Sans4.8%
Poppins4.4%
Manrope3.6%
IBM Plex Mono3.5%
Montserrat2.9%
Roboto2.6%

Typewolf's index

TypefaceShare of sites
Inter4.3%
Helvetica Neue2%
Poppins1.6%
Montserrat1.5%
Roboto1.4%
Founders Grotesk1.4%
Graphik1.2%
Open Sans1.2%
Canela1%
DM Sans1%

How this was measured

  • One homepage per company, loaded in Chrome between 2026-09-16 and 2026-09-17.
  • A typeface counts when it renders visible text. A font file that loads but draws nothing is not counted.
  • Web-font packaging is merged into the family: Graphik Web counts as Graphik.
  • Company websites, batches and industries come from the yc-oss/api dataset of the Y Combinator directory. Only companies marked active are included.
  • The main heading is the largest text on the page; body text is the typeface with the most characters at 22px or smaller.