Anthropic releases Claude 3.5 Sonnet
Claude 3.5 Sonnet released — the first Claude 3.5 model, $3/$15 per 1M tokens with a 200K context window, launched alongside Artifacts
Why it matters
Anthropic said it outperforms Claude 3 Opus at twice its speed and at mid-tier Sonnet pricing; on an internal agentic coding evaluation it solved 64% of problems (Claude 3 Opus: 38%). The UK AISI ran a pre-deployment safety evaluation, and Anthropic's red teaming concluded it remains at ASL-2
Source — Primary sources first; secondary reports are labelled “Press”
Officialanthropic.comhttps://www.anthropic.com/news/claude-3-5-sonnetAdded in Week 41, 2026 · See that week