Introducing Claude Opus 4.5

Summary

Claude Opus 4.5 is available today across Claude apps, the API, and all three major cloud platforms, with the model identifier claude-opus-4-5-20251101 and pricing of $5/$25 per million tokens. The announcement positions it as a state-of-the-art model for coding, agents, computer use, deep research, spreadsheets, and slides, while reporting stronger vision, reasoning, and mathematics than predecessors. On the Claude API, an effort parameter lets developers trade off speed and spend against capability; at medium effort, Opus 4.5 matched Sonnet 4.5’s best SWE-bench Verified score using 76% fewer output tokens, while highest effort exceeded it by 4.3 percentage points using 48% fewer tokens. Additional platform changes include context compaction, advanced tool use, memory, and improved multi-agent coordination. Product updates add Claude Code’s editable Plan Mode and desktop sessions, automatic conversation summarization, and expanded Claude for Chrome and Excel access.

Takeaways

1. 1

   The model is available through Claude apps, the API, and all three major cloud platforms at $5 per million input tokens and $25 per million output tokens.

2. 2

   At medium effort, Opus 4.5 matched Sonnet 4.5’s best SWE-bench Verified score while using 76% fewer output tokens; at highest effort, it scored 4.3 percentage points higher using 48% fewer tokens.

3. 3

   Claude Code adds a user-editable plan.md workflow and desktop support for running multiple local and remote sessions in parallel.