Claude Opus 4.6

Anthropic·Jan 2026reasoningproprietary

Claude Opus 4.6 (January 2026) brought the 1M-token context window to the Opus tier at standard pricing — previously a beta perk of Sonnet — and posted frontier-range human-preference results. It started the fast 4.6 → 4.7 → 4.8 cadence of 2026; most of its capabilities are strictly improved in 4.8 at identical prices.

Benchmark results

Where it shines

  • 1M context at standard $5/$25 pricing
  • Frontier-class chat quality and writing
  • Version-pinnable for long-lived deployments

Alternatives to Claude Opus 4.6

Qwen3-Max

Alibaba's trillion-parameter API flagship — frontier-adjacent quality with strong agentic tool use at mid-tier prices.

GPT-5.5

OpenAI's flagship reasoning model with a 1M-token context window, built for hard coding, science and long-horizon agentic work.

Gemini 3 Pro

Google's November 2025 frontier breakout — 91.9% GPQA Diamond and 37.5% HLE made it the reasoning leader of its generation.

Gemini 2.5 Pro

Google's 2025 workhorse flagship — first mainstream thinking model with a 1M context, still widely deployed.

Frequently asked questions

How much does the Claude Opus 4.6 API cost?
Claude Opus 4.6 costs $5 per million input tokens and $25 per million output tokens, with cached input at $0.5 per million. A workload of 10M input and 1.5M output tokens per month costs about $87.50.
What is the context window of Claude Opus 4.6?
Claude Opus 4.6 supports a context window of 1,000,000 tokens (1M), with up to 64K output tokens per response.
Is Claude Opus 4.6 open source?
No — Claude Opus 4.6 is a proprietary model available through Anthropic's API and partner platforms.
What are the best alternatives to Claude Opus 4.6?
The closest alternatives by overall capability are Qwen3-Max, GPT-5.5, Gemini 3 Pro, Gemini 2.5 Pro. See the comparison pages for detailed head-to-head breakdowns.