Introducing Sonnet 4.6

Source: Anthropic Date: 2026-02-17 URL: https://www.anthropic.com/news/claude-sonnet-4-6

Summary

Anthropic released Claude Sonnet 4.6 on February 17, 2026 as the new default model on Free and Pro plans, at the same price point as Sonnet 4.5 ($3/$15 per million tokens). Headline upgrades: 1M-token context window (beta), substantially improved computer use, better long-horizon planning, and code generation that developers preferred ~70% of the time over Sonnet 4.5 in internal testing. Users chose it over Opus 4.5 ~59% of the time, marking it as Opus-competitive at Sonnet pricing.

Implications

• The pricing hold at $3/$15 while delivering near-Opus performance continues the capability-per-dollar compression trend — the same dynamic compressing enterprise AI budgets and raising the floor for what “acceptable” baseline models look like.
• 1M-token context in beta is the most agentic-relevant capability: it moves Sonnet 4.6 into territory where full codebase or document corpus fits in a single context, reducing retrieval architecture complexity for agent systems.
• Computer use gains on OSWorld compound quickly for agentic workflows — this is the capability axis most directly relevant to desktop and browser automation, where the gap between models has been largest.
• Sonnet 4.6 becoming the free-tier default accelerates its adoption as the ambient baseline for Claude integrations, which matters for anyone depending on Claude API behavior — downstream agents built on Sonnet will inherit these characteristics without explicit version pinning.