Anthropic switched to HTML artifacts because they deliver clearer layouts and...

https://sierra-wiki.win/index.php/HTML_Artifacts_vs_Markdown_for_Design_Reviews:_Which_Gets_Better_Feedback%3F

Anthropic switched to HTML artifacts because they deliver clearer layouts and better formatting, boosting team productivity. Their internal reports now load 5 times faster than before, helping engineers review code and plan designs without delays