Sphinx of black quartz, judge my vow.
The quick brown fox jumps over the lazy dog. 0123456789
Weights:
400 600
CSS
font-family: 'optimisticAI', sans-serif;muse.ai/
muse.ai
13 fonts found
Muse — Your Personal AI Agent from Meta
Try Muse, your personal AI agent that gets things done. Give Muse a goal or an everyday task and it handles the rest, from finances and health to shopping and the people you care about.
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What fonts does Muse use?
Muse.ai uses optimisticAI, Optimistic AI Text, hatchLetterCaveat, optimisticMono and optimisticText as its main typefaces. Arial, Roboto, helvetica-neue and Segoe UI are declared as fallbacks. 13 fonts detected, last checked Nov 7, 2026.
Sphinx of black quartz, judge my vow.
The quick brown fox jumps over the lazy dog. 0123456789
Weights:
400italic
CSS
font-family: 'Optimistic AI Text', sans-serif;Sphinx of black quartz, judge my vow.
The quick brown fox jumps over the lazy dog. 0123456789
Weights:
300
CSS
font-family: 'optimisticText', sans-serif;Sphinx of black quartz, judge my vow.
The quick brown fox jumps over the lazy dog. 0123456789
Weights:
400 700
CSS
font-family: 'hatchLetterCaveat', sans-serif;Sphinx of black quartz, judge my vow.
The quick brown fox jumps over the lazy dog. 0123456789
Weights:
300 800
CSS
font-family: 'optimisticMono', sans-serif;Fallback fonts
These fonts are listed in the CSS as backups. The browser only falls back to them if the main fonts above fail to load.
Font stacks
The cascading font order declared in CSS. Browsers try each font left-to-right until one is available.
Legend:AaCustom font (primary)AaSystem fontkwCSS keyword (generic)
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Frequently asked questions about Muse.ai's fonts
What fonts does Muse.ai use?
Muse.ai uses optimisticAI, Optimistic AI Text, hatchLetterCaveat, optimisticMono and optimisticText as its main typefaces. Arial, Roboto, helvetica-neue and Segoe UI are declared as fallbacks. 13 fonts detected, last checked Nov 7, 2026.