Claude Sonnet 5.5 joins Arena.ai Agent Arena and Battle Mode
Arena.ai has added Claude Sonnet 5.5 by AnthropicAI to Agent Arena and to Battle Mode for WebDev, Text, Vision, and Document. Claude says it is the second Claude 5.5 model, runs more than 30% faster than Sonnet 5, and costs up to 30% less for most work.