The typeface on duolingo.com is KaTeX_Main, KaTeX_SansSerif and KaTeX_Size1, loaded across 60 @font-face declarations. Every font family, weight and source on this page is read straight from the live CSS — no image guessing, no machine learning, just the rules the browser used.
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Main, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_SansSerif, Georgia, 'Times New Roman', serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Size1, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Fraktur, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Math, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Size2, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Size4, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Typewriter, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_AMS, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Caligraphic, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Script, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
The quick brown fox jumps over the lazy dog
font-family: KaTeX_Size3, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
Get Font Info inspected the homepage of duolingo.com and parsed 2 stylesheets totalling 141.3 KB. Inside those stylesheets we found 60 @font-face declarations — the rules a browser uses to download and register a custom typeface. The primary typefaces are served from custom web font, and 34 CSS rules reference them across the page.
Open the live inspector and hover any text on duolingo.com to see the exact font, weight, size and line-height for that element.
Open live font inspector for duolingo.comduolingo.com uses KaTeX_Main, KaTeX_SansSerif and KaTeX_Size1 as its primary typefaces. These fonts are loaded from a self-hosted webfont and applied across 34 CSS rules on the homepage.
duolingo.com loads its fonts from a self-hosted webfont. Get Font Info detected 60 @font-face declarations across 2 stylesheets on the live page.
duolingo.com loads KaTeX_Main in 2 weights: 400, 700. If you want to match the look, request the same weights from your font host so you only ship what's actually used.
Yes — once you know the font name, you can load it from the same source. If KaTeX_Main isn't a fit (licensing, weight selection, look-and-feel), close alternatives include Inter, Manrope and DM Sans. Use the CSS snippet on this page as a starting point.
These fonts are self-hosted webfonts. They may be licensed commercially from a type foundry, custom-made for the brand, or freely available — you would need to identify the typeface and check its license at the foundry.
Compare the typography on duolingo.com with how other well-known sites load and use their fonts.
This page lists the fonts loaded by the homepage of duolingo.com. Get Font Info reads the live CSS — every @font-face rule, every font-family declaration — so you see the exact fonts the browser used, not an image-based guess.
More guides: find a font used on a website, identify fonts from a website, what typeface is this website using, or font checker.