What font does causal.so use?

causal.so uses Manrope Variable, Inter Variable, ui-monospace. Headlines are set in Manrope Variable and body text in Inter Variable, measured from the site as it renders, not read from its stylesheet.

Is the causal.so font free to use?

No. Manrope Variable is a licensed font that causal.so serves itself. The closest free match is Manrope, Inter, available on Google Fonts. The CSS on this page puts it in the font stack as the stand-in.

How do I get the same typography as causal.so in my project?

Download the causal.so design pack from Stylepack: it holds the font stack, the type scale, every text style and the screenshots, in a form an AI coding agent such as Claude Code or Cursor can build from.

causal.so fonts | Stylepack

Font families

3 families

CSS to reproduce it

Font variables with the free stand-in in the stack, so the same CSS works with or without the licensed font.

1:root {
2  --font-heading: "Manrope Variable", "Manrope", sans-serif; /* Manrope stands in for Manrope Variable */
3  --font-body: "Manrope Variable", "Manrope", sans-serif; /* Manrope stands in for Manrope Variable */
4  --font-mono: "ui-monospace", monospace;
5  --font-size-base: 14px;
6}

How the type is set

headline-displayQuick brown foxManrope Variable / 60px / 700 / lh 72px

headline-lgQuick brown foxManrope Variable / 50px / 650 / lh 70px

headline-mdQuick brown foxManrope Variable / 24px / 600 / lh 38px

body-mdThe quick brown fox jumps over the lazy dogInter Variable / 14px / 400 / lh 22.4px

label-mdThe quick brown fox jumps over the lazy dogManrope Variable / 16px / 500 / lh 23px

buttonThe quick brown fox jumps over the lazy dogManrope Variable / 20px / 600 / lh 30px

codeconst pack = extract(url)ui-monospace / 12px / 350 / lh 18px

Font sizes in use

1214162024405060

For AI agents

The pack is plain text, no key: fetch DESIGN.md, or hand the whole pack to Claude Code, Cursor or Copilot with the MCP server.

curl -s https://stylepack.ai/packs/causal.so/DESIGN.md

The fonts causal.so uses