Term
Claude Sonnet 4.6
Claude Sonnet 4.6 is Anthropics mid-tier model from February 2026 — close to Opus-level performance, with a 1M-token context and unchanged Sonnet pricing of 3/15 USD per million tokens.
Claude Sonnet 4.6 — explained in more detail
Anthropic released Claude Sonnet 4.6 on February 17, 2026 as the new mid-tier model of the Claude range. It is a full upgrade across coding, computer use, long-context reasoning, agent planning and knowledge work, and according to Anthropic it approaches the performance of the November 2025 flagship Opus 4.5 — at a substantially lower price. The model offers a 1M-token context window along with stronger safety and resistance to prompt injection.
Example / Practical use
At launch, Sonnet 4.6 replaced its predecessor as the default model across Anthropics own surfaces — the Claude.ai web app, the Claude Cowork productivity suite and the Claude Code development environment. On the same day it also rolled out generally in GitHub Copilot. Pricing stayed at Sonnet level: 3 USD per 1M input tokens and 15 USD per 1M output tokens. This makes Sonnet 4.6 particularly suited to agentic coding pipelines and enterprise workflows where a strong price-performance ratio across many requests matters.
Distinction
Sonnet is Anthropics mid-tier line between the compact Haiku and the top-tier Opus. While Opus (e.g. Opus 4.5/4.6) stands for maximum performance at a correspondingly higher price of 5/25 USD per million tokens, Sonnet 4.6 targets near-comparable quality at one fifth of the output price. Sonnet 4.6 differs from pure coding tools such as Claude Code in that it is the underlying language model, not the application.
Discover more
AI Recap July 2026: Two Anthropic Models, a Government Review and the Open-Weight Pressure
July 2026 in AI: Sonnet 5 and Opus 5 from Anthropic, GPT-5.6 after a US review, Kimi K3 as open weights, and new GEO controls in Search Console.
GlossaryClaude Fable 5.1
Anthropic's flagship Claude Fable model, released on 1 September 2026. A frontier model for demanding reasoning, coding, research and long-running agents; 1M-token context, multimodal input, proprietary access via API and the Claude apps.
EncyclopediaComparing AI models — who builds what and how to choose
The major model families in 2026 at a glance. Who builds Claude, GPT, Gemini, Llama, Mistral, DeepSeek, Qwen — and which model to pick when.