On February 17, 2026, Anthropic released Claude Sonnet 4.6. The model ID is claude-sonnet-4-6, and it became the default model for Free and Pro users on claude.ai and Claude Cowork at launch. Anthropic describes it as "the best combination of speed and intelligence." Pricing stays the same as Sonnet 4.5 at $3 / $15 per million input/output tokens.
Highlights
- Upgrades across coding, computer use, and knowledge work — Anthropic reports gains over the prior Sonnet model in coding, computer use, long-context reasoning, agent planning, and design.
- Opus-class work at lower cost — Anthropic states that "performance that would have previously required reaching for an Opus-class model — including on real-world, economically valuable office tasks — is now available with Sonnet 4.6."
- Default for Free and Pro — It became the default model on claude.ai and Claude Cowork at launch.
- Long context — Supports a 1M-token context window (beta).
Spec summary
- Model ID:
claude-sonnet-4-6 - Pricing:
$3input /$15output per MTok - Context window: 1M tokens (beta)
- Max output: 64K tokens (sync Messages API); up to 300K via the
output-300k-2026-03-24beta header on the Message Batches API. - Extended thinking: Yes · Adaptive thinking: Yes
- Reliable knowledge cutoff: August 2025
Figures are based on Anthropic's official model docs (platform.claude.com) and the launch announcement (anthropic.com/news/claude-sonnet-4-6). For specific benchmark scores, please refer to the official announcement.