Claude Opus 4.5 — reviews, specs & pricing
Top-of-the-line Claude for the hardest tasks — deep reasoning, complex agents, careful writing. Expensive.
Summary
Claude 4.5 Opus is Anthropic's flagship model designed to tackle the most demanding cognitive tasks, offering unmatched depth in reasoning and precision. It is the premier choice for complex software engineering, multi-step agentic workflows, and highly nuanced creative or technical writing. While it sets a new benchmark for intelligence, its elite performance is accompanied by premium pricing and higher latency.
Sample use case
A multinational financial services firm can utilize Claude 4.5 Opus to power autonomous developer agents that safely migrate monolithic legacy codebases to cloud-native microservices. The model can ingest thousands of lines of undocumented legacy code, map complex dependency trees, systematically refactor the logic into clean Python, and automatically write comprehensive unit and integration tests.
Specifications
- Provider: anthropic
- License: closed
- Context: 200k tokens
- Input price: $15/M tok
- Output price: $75/M tok
Pros
- Unparalleled deep reasoning and analytical logic
- Exceptional multi-step agentic capabilities
- Meticulous, highly nuanced writing quality
- Superior complex coding and architecture design
Cons
- Significantly higher cost per token
- Slower generation speeds and higher latency
- Overkill for simple, high-volume tasks
Average rating 3.2 from 5 community reviews on Reviuws.
Benchmark results
| Benchmark | Score | Latency |
|---|
| AIME 2024 | 90.0% | — |
|---|
| MMLU-Pro | 89.0% | — |
|---|
| GPQA Diamond | 87.0% | — |
|---|
| SWE-bench Verified | 80.9% | — |
|---|
| MMMU | 80.7% | — |
|---|
| Terminal-Bench | 59.3% | — |
|---|
Measured by the Reviuws Bench suite on identical prompts. Compare these scores against every other model.
Community reviews
Simon Willison's blog on Claude Opus 4.5
Rating: 4.0 / 5 — by Simon Willison (use case: coding and agentic workflows)
Willison notes Opus 4.5 landed in a suddenly crowded top tier alongside GPT-5.1-Codex-Max and Gemini 3, making a clear 'best model' call harder than ever. He rates it a strong, well-rounded coding and agent model while staying cautious about self-reported superlatives.
Pros: Much cheaper than earlier Opus versions; strong coding, agent and computer-use results.
Cons: Still pricier than GPT-5.1 and Gemini 3 Pro; benchmark claims hard to verify independently.
ZDNET on Claude Opus 4.5
Rating: 2.0 / 5 — by David Gewirtz (use case: practical coding tasks)
Gewirtz ran four practical coding tests against the 'best in the world for coding' claim and Opus 4.5 passed only two, crashing on one and turning in a mediocre result on another. He concludes the marketing claim doesn't survive real-world testing.
Pros: Handled two of four real-world coding tasks well.
Cons: Crashed on one test; file-handling glitches broke basic plugin testing.
TechCrunch on Claude Opus 4.5
Rating: 3.0 / 5 — by Russell Brandom (use case: everyday productivity)
TechCrunch covers Opus 4.5 as the final release in the 4.5 series, highlighting new Chrome and Excel integrations plus indefinitely long chats via auto-summarisation.
Pros: Native Chrome and spreadsheet integrations; effectively unlimited chat length.
Cons: Largely descriptive of Anthropic's claims; no independent benchmarking.
Ars Technica on Claude Opus 4.5
Rating: 3.0 / 5 — by Samuel Axon (use case: long-running conversations)
Ars frames Opus 4.5 around its price cut versus Opus 4.1 and much longer conversations, answering a long-standing criticism of Claude's context limits, while keeping journalistic distance from Anthropic's superiority claims.
Pros: Substantially cheaper API pricing; far longer uninterrupted sessions.
Cons: Still more expensive than rival frontier models; bold claims unverified.
Tom's Guide on Claude Opus 4.5
Rating: 4.0 / 5 — by Amanda Caswell (use case: everyday assistant prompts)
Caswell pitted Opus 4.5 against ChatGPT-5.2 on real-life prompts and found it the more consistently useful of the two, calling it the clear winner across the everyday scenarios she tried.
Pros: More helpful on everyday prompts than ChatGPT-5.2; consistent across varied tasks.
Cons: Small, subjective prompt set; doesn't test the coding claim.
Frequently asked questions
What is Claude Opus 4.5?
Claude 4.5 Opus is Anthropic's flagship model designed to tackle the most demanding cognitive tasks, offering unmatched depth in reasoning and precision. It is the premier choice for complex software engineering, multi-step agentic workflows, and highly nuanced creative or technical writing. While it sets a new benchmark for intelligence, its elite performance is accompanied by premium pricing and higher latency.
How much does Claude Opus 4.5 cost?
Claude Opus 4.5 costs $15 per million input tokens and $75 per million output tokens.
Is Claude Opus 4.5 open source?
Claude Opus 4.5 is released under the closed license.