What font does OpenAI use?
OpenAI introduced a custom typeface with its 2025 brand refresh. On the website one family does everything, mostly at medium weight, which gives the pages their even, quiet texture.
Short answer: OpenAI’s website uses OpenAI Sans, the company’s own typeface, for all of its text. The font files are served from OpenAI’s CDN.
OpenAI Sans
Self-hosted100%- CSS name
OpenAI Sans- Weights
- 400, 500, 600
- Sizes
- 48px · 18px · 17px · 16px · 14px · 13px
- Served from
- cdn.openai.com
Sizes, weights and spacing by role
These are computed values from the live page, which is what the Font Inspector panel shows when you click each element.
| Role | Font | Size | Weight | Line height | Letter spacing |
|---|---|---|---|---|---|
| Headline | OpenAI Sans | 48px | 500 | 1.16 | -0.03em |
| Body text | OpenAI Sans | 18px | 500 | 1.32 | -0.01em |
| Navigation | OpenAI Sans | 17px | 400 | 1.65 | -0.01em |
The main font stack in the CSS:
font-family: "OpenAI Sans", "OpenAI Sans Variable Scripts", sans-serif;- Both the headline and the larger body text use weight 500. Hierarchy comes from size, not from bold.
- Letter spacing is slightly negative throughout, from -0.03em on headlines to -0.01em on text.
- The page also declares fonts it only uses elsewhere, including KaTeX fonts for mathematics.
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 openai.com or anywhere else, and lists every font on the page. Free, no account.
About the fonts, and whether you can use them
OpenAI Sans
A custom geometric sans serif made for OpenAI, with round, open letterforms. The CSS also declares a variable companion for other writing systems.
Can you use it? OpenAI Sans is proprietary and cannot be licensed. Open source geometric sans serifs such as DM Sans and Outfit give a similar clean, round feel.
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 DM Sans, which is open source, with the sizes and spacing measured above. It is an approximation, not a copy of OpenAI’s brand typeface.
/* Approximates the OpenAI look with a free font */
body {
font-family: "DM Sans", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
}
h1 {
font-size: 3rem; /* 48px */
font-weight: 500;
line-height: 1.16;
letter-spacing: -0.03em;
}
p {
font-size: 1.125rem; /* 18px */
font-weight: 500;
line-height: 1.32;
letter-spacing: -0.01em;
}How we checked
We opened openai.com in Chrome on September 20, 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.
OpenAI and its typefaces are trademarks of their respective owners. Font Inspector is not affiliated with OpenAI.
Questions & answers
What font does OpenAI use on its website?+
OpenAI’s website uses OpenAI Sans, the company’s own typeface, for all of its text. The font files are served from OpenAI’s CDN.
Can I use the OpenAI font?+
OpenAI Sans is proprietary and cannot be licensed. Open source geometric sans serifs such as DM Sans and Outfit give a similar clean, round feel.
What is a free font similar to OpenAI Sans?+
DM Sans and Outfit are free on Google Fonts and give a similar feel. No free font is an exact match, so compare it with your own text first.
How can I check what font OpenAI uses myself?+
Open openai.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.