Model Drop

Claude Opus 4.5

November 24, 2025 2 min read

Claude Opus 4.5, which Anthropic shipped on November 24, 2025, is Anthropic's flagship model for coding, agents and computer use, sold at a third of the old Opus price.

Model: Claude Opus 4.5 (claude-opus-4-5-20251101)
Maker: Anthropic
Ship date: November 24, 2025
Pricing: $5 / $25 per M tokens
Context: 200K tokens
Where you can use it:
- Claude.ai and the Claude apps
- Claude Code and the Claude API
- Amazon Bedrock, Vertex AI, Microsoft Foundry
When to reach for it:
- Long agentic coding and big refactors
- Computer use, spreadsheets and slides
- Skip it for cheap, high-volume calls
How it compares:
- Ahead of Gemini 3 Pro and GPT-5.1 at coding
- Trails Gemini 3 Pro on science questions
What makes it different:
- Opus power at a third of the old price
- New effort setting trades depth for cost
Early reactions: Testers welcomed the much lower Opus price and strong coding, though some found it hard to tell apart from Sonnet 4.5 in daily work.
Read more: Introducing Claude Opus 4.5, Claude Opus 4.5 system card

The benchmarks

Anthropic ran most tests with a 64K thinking budget at the default high effort, averaged over 5 trials (SWE-bench Verified and MCP Atlas with no thinking, Terminal-Bench 2.0 with 128K), against Claude Sonnet 4.5, Claude Opus 4.1, Gemini 3 Pro and GPT-5.1 (plus GPT-5.1-Codex-Max on coding); rival scores are the makers' own, and a footnote says Anthropic's own reruns lifted Gemini 3 Pro to 56.7% and GPT-5.1 to 48.6% on Terminal-Bench 2.0.

Anthropic's numbers

SWE-bench Verified (real GitHub fixes): 80.9%. +4.7 over Gemini 3 Pro (76.2%), +4.6 over GPT-5.1 (76.3%), +3.0 over GPT-5.1-Codex-Max (77.9%), +3.7 over Claude Sonnet 4.5 (77.2%).
Terminal-Bench 2.0 (command-line agent tasks): 59.3%. +5.1 over Gemini 3 Pro (54.2%), +11.7 over GPT-5.1 (47.6%), +1.2 over GPT-5.1-Codex-Max (58.1%), +9.3 over Claude Sonnet 4.5 (50.0%).
MCP Atlas (large-scale tool use): 62.3%. +18.5 over Claude Sonnet 4.5 (43.8%), +21.4 over Claude Opus 4.1 (40.9%).
OSWorld-Verified (operating a computer): 66.3%. +4.9 over Claude Sonnet 4.5 (61.4%), +21.9 over Claude Opus 4.1 (44.4%).
ARC-AGI-2 (novel visual puzzles): 37.6%. +6.5 over Gemini 3 Pro (31.1%), +20.0 over GPT-5.1 (17.6%), +24.0 over Claude Sonnet 4.5 (13.6%).
GPQA Diamond (grad-level science): 87.0%. +3.6 over Claude Sonnet 4.5 (83.4%), −1.1 under GPT-5.1 (88.1%), −4.9 under Gemini 3 Pro (91.9%).
MMMU (visual reasoning): 80.7%. +2.9 over Claude Sonnet 4.5 (77.8%), −4.7 under GPT-5.1 (85.4%).

Independent numbers

Artificial Analysis Intelligence Index (current v4.3.2, AA estimate): 29.1. +1.1 over Gemini 3 Pro (28.0), +4.4 over GPT-5.1 (high) (24.7).
ARC-AGI-1 (ARC Prize, 64K thinking): 80.00%. +5.00 over Gemini 3 Pro (75.00%), +7.17 over GPT-5.1 (high) (72.83%).