Anthropic launches Claude Sonnet 5, closing agentic gap with Opus 4.8 at lower cost

Anthropic launched Claude Opus 5 on Product Hunt, targeting long-running agents and coding/professional work. They claim near-Fable 5 intelligence at half the price. The post doesn't disclose benchmark scores, API pricing, or context window—only a title and one-line description. I'd hold off until we see real evals and a pricing table.

Anthropic released Claude Sonnet 5 today, calling it the most agentic Sonnet yet with planning, browser/terminal tool use, and a 1M-token context window. Pricing stays at $3/$15 per million tokens, with a promo rate of $2/$10 through late August. The community reaction was muted: benchmarks show it consumed more tokens than Fable, and one test found it cost more than Opus 4.8. The post confirms Fable/Mythos 5 were approved for re-release after government work, but gives no timeline.

Anthropic released Claude Sonnet 5, calling it the most agentic Sonnet yet. It plans, uses browsers and terminals, and beats Sonnet 4.6 across all benchmarks. On the real-world knowledge work test GDPval-AA v2, it edges past Opus 4.8 with 1,618 vs 1,615 points. Agentic coding on SWE-bench Pro hits 63.2%, still behind Opus 4.8 at 69.2% but well above 4.6's 58.1%. Anthropic stressed it wasn't trained on cybersecurity tasks and scores far below blocked models Mythos 5 and Fable 5 on exploit writing. Real-time cyber safeguards are on by default. Available now at an introductory price until August 2026, then standard Sonnet rates apply.

Anthropic released Claude Sonnet 5, a midsize model that can plan, use tools like browsers and terminals, and run autonomously at a lower price. The company says this agentic capability required larger, pricier models just months ago. It directly competes with OpenAI's GPT-5.6 Sol preview and Google's Gemini 3.5 Flash, both pitched as agent-first tools. The post does not disclose specific pricing or benchmark scores, so the real cost savings are still unconfirmed.

Claude Sonnet 5 is Anthropic's most agentic mid-tier model yet—it plans, uses browsers and terminals, and runs autonomously. Its agentic performance jumps well past Sonnet 4.6 and lands close to Opus 4.8, at $3/$15 per million input/output tokens (introductory $2/$10 through Aug 31, 2026). Safety evals show fewer undesirable behaviors than Sonnet 4.6 and far lower cybersecurity capability than Opus models. Early testers report it finishes multi-step tasks end-to-end without stalling and checks its own output unprompted.