Term
Claude Opus 4.5
Claude Opus 4.5 is Anthropic's top-tier model from November 2025 — the direct predecessor of Opus 4.6, bringing "Infinite Chats" and substantially reduced token usage.
Claude Opus 4.5 — explained in more detail
Anthropic released Claude Opus 4.5 on November 24, 2025 as the then-flagship of the Claude 4 family. The improvements focused on coding and workplace tasks such as spreadsheets, slides and document work. Anthropic positioned it as “the best model in the world for coding, agents and computer use” and reported gains in both deep research and office workflows.
Example / Practical use
New with Opus 4.5 was the Infinite Chats feature, which softens context-window-limit errors by transparently compressing older parts of the conversation. On Anthropic’s internal coding benchmarks, the model improved results while cutting token usage by roughly half — particularly relevant for code migration and refactoring. Opus 4.5 was available on Claude.ai, the Anthropic API and on AWS Bedrock, GCP Vertex AI and Azure. Pricing: $5 per 1M input tokens, $25 per 1M output tokens — identical to the 4.6 generation. It was succeeded by Opus 4.6 in February 2026.
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