The most important thing about Sonnet 5.5 is that it's now the model that powers the free tier on https://claude.ai - so all of this stuff can be done by free users ChatGPT's free tier is still GPT-5.6 Luna, which is a lot less capable

Claude@claudeai1h ago

A thread of early experiments with Claude Sonnet 5.5. A fall foliage simulator by @_re_pete, made with Sonnet 5 vs Sonnet 5.5.