Anthropic switched to HTML artifacts instead of Markdown for internal planning,...

https://www.slideserve.com/aaron_ward92/what-s-a-practical-html-artifact-layout-for-a-code-review-with-3-findings

Anthropic switched to HTML artifacts instead of Markdown for internal planning, code reviews, design systems, and reports because HTML lets them control formatting precisely and scale better. This change cut output costs to just $0