Anthropic LLM Big Closed weights

Claude Opus 4.6

280 days since Anthropic announced it · 5 Feb 2026

Claude Opus 4.6 is a closed-weights LLM from Anthropic, announced 5 Feb 2026. It costs $5 per 1M input tokens and $25 per 1M output tokens. Its context window is 1M tokens.

Input: $5; per 1M tokens
Cache write: $6.25; per 1M tokens
Cache read: $0.50; per 1M tokens
Output: $25; per 1M tokens
Context window: 1M; tokens
Parameters: —; not disclosed

Announcement: anthropic.com/news/claude-opus-4-6
Docs: platform.claude.com/docs/en/models/opus-4-6/overview

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Anthropic · Big · Opus

closed weights

A new one every ~60 days — due in ~9d.

Claude Opus 5.5 +60d 22 Sep 2026
Claude Opus 5 +57d 24 Jul 2026
Claude Opus 4.8 +42d 28 May 2026
Claude Opus 4.7 +70d 16 Apr 2026
Claude Opus 4.6 +73d 5 Feb 2026
Claude Opus 4.5 +111d 24 Nov 2025
Claude Opus 4.1 5 Aug 2025