Claude Sonnet 5 Launches as New Default Model, Delivering Near-Opus Performance at Lower Cost

Summary: Anthropic launched Claude Sonnet 5 on June 30, replacing the previous Sonnet as the default model across Free and Pro plans — delivering near-Opus 4.8 capability at roughly half the cost.

Key Facts

• Default model upgrade: Immediately replaces Sonnet 4.6 for Free and Pro users; also available on Max, Team, and Enterprise plans
• Performance closes the gap with Opus 4.8 — measurable gains over Sonnet 4.6 on reasoning, tool use, coding, and agentic benchmarks
• Launch pricing: $2 per million input tokens / $10 per million output tokens through August 31, rising to $3/$15 thereafter
• Available simultaneously in Claude.ai, Claude Code, the API, and GitHub Copilot
• Handles browser and terminal tool use plus long-horizon autonomous runs at mid-tier cost

Why It Matters

Sonnet 5 effectively lowers the price floor for production-grade agentic workflows. Until recently, reliable multi-step agent execution required Opus-class models. Enterprises planning large-scale agent deployments now have a cheaper baseline that doesn't require compromising on capability — a meaningful shift in the cost-performance calculus.

Read More

• Introducing Claude Sonnet 5 — Anthropic
• Anthropic launches Claude Sonnet 5 — TechCrunch
• Claude Sonnet 5 now on GitHub Copilot — GitHub