Claude Sonnet 5 Launches as Anthropic's New Default Model
View original source →On June 30, 2026, Anthropic released Claude Sonnet 5, a new mid-size model designed for autonomous, multi-step task execution at a fraction of flagship model costs. Sonnet 5 is now the default model for all Free and Pro Claude users.
The model can independently browse the web to research topics, summarize findings, write code based on that research, run the code, and iterate if it fails — completing in one session what previously required multiple back-and-forth exchanges.
Key points:
• Performance benchmarks show Sonnet 5 approaching Claude Opus 4.8 on most standard tests, particularly in software engineering tasks and multi-step reasoning
• Introductory pricing is set at $2 per million input tokens and $10 per million output tokens through August 31, 2026 — roughly one-seventh the cost of Opus 4.8
• After September 1, pricing moves to $3 per million input tokens and $15 per million output tokens
• Available immediately via Claude Platform, Claude.ai, Claude Code, Claude Cowork, and through APIs on Amazon Bedrock, Google Cloud Vertex AI, and Microsoft Foundry
• The release came the day before Fable 5's restoration, giving Claude users two significant capability upgrades in 48 hours
The price-performance shift is likely to accelerate enterprise adoption of agentic workflows significantly. The cost barrier that previously made autonomous AI pilots expensive to run at scale is now substantially lower.
Why It Matters: Sonnet 5 lowers the cost barrier that has kept agentic AI workflows confined to enterprise pilots with large budgets. Running continuous autonomous AI agents on real business workflows is now economically viable for organizations of almost any size — and the baseline capability of what consumers get has taken a significant step forward.