Curious about the design behind claude.ai? SiteFontCheck scanned their live CSS architecture and identified 3 unique font families. The website relies heavily on <anthropic-sans, system-ui, segoe ui, roboto, helvetica, arial, sans-serif, ui-sans-serif, system-ui, -apple-system, segoe ui, roboto, sans-serif> for its main text elements, paired with <anthropicons-variable> and <anthropic-serif, anthropic serif fallback georgia, anthropic serif fallback times, anthropic serif fallback dejavu, anthropic serif fallback noto, georgia, arial hebrew, noto sans hebrew, times new roman, times, pingfang sc, microsoft yahei, noto sans cjk sc, pingfang tc, microsoft jhenghei, noto sans cjk tc, hiragino sans, yu gothic, meiryo, noto sans cjk jp, apple sd gothic neo, malgun gothic, noto sans cjk kr, serif> as fallback options. Below is the precise map of font sizes, weights, and text elements used across their site.