Claude Opus 4.6 Review: The Best Reasoning Model You Can Buy
Pros
- Best-in-class reasoning and complex problem solving
- 200K context window with near-perfect recall
- Exceptional instruction following and nuance
- Industry-leading safety with minimal false refusals
Cons
- Most expensive model in the Claude lineup
- Slower throughput than Sonnet for simple tasks
- No built-in image generation
After two weeks of intensive testing across coding, analysis, creative writing, and agentic tasks, Claude Opus 4.6 emerges as the most capable AI model available for complex reasoning work. But it comes with tradeoffs that matter.
Reasoning and Problem Solving
Where Opus 4.6 shines brightest is in multi-step reasoning tasks. Given a complex legal brief, a systems design problem, or a thorny debugging session, Opus consistently outperforms every competitor we tested — including GPT-5 and Gemini Ultra 2.
In our standard reasoning battery (100 questions requiring 5+ steps), Opus 4.6 scored 94/100, compared to GPT-5’s 91/100 and Gemini Ultra’s 88/100.
Coding Performance
On a curated set of 50 real-world engineering tasks drawn from actual GitHub issues:
- Opus 4.6: 87% fully correct solutions
- GPT-5: 85% fully correct solutions
- Gemini Ultra 2: 81% fully correct solutions
The difference is clearest in tasks requiring architecture reasoning — Opus tends to ask clarifying questions and consider edge cases before committing to an implementation.
Context and Memory
The 200K context window handles entire codebases without degradation. We tested with a 180K-token repository and Opus consistently recalled details from the beginning, middle, and end of context — something that still trips up competing models.
Value Assessment
At $15/1M input tokens, Opus 4.6 is 5x the price of Claude Sonnet 4.6. For tasks where output quality directly drives business value (legal analysis, complex code review, research synthesis), it’s worth every cent. For everyday chat and simple tasks, use Sonnet.
Verdict
Claude Opus 4.6 is the gold standard for AI reasoning today. If you need the best, this is it — just make sure your use case justifies the cost.