How to use Claude Opus 4.5 in production
A practical guide to claude-opus-4-5, using data from the AI & LLM Index. The goal is a shortlist and a decision, not a tour of every option.
What Claude Opus 4.5 is
Claude Opus 4.5 is a frontier model from Anthropic, released in 2026-08-08. Claude Opus 4.5 is a frontier model from Anthropic. It offers a 400,000-token context window, costs $19.42 per million input tokens and $75.27 per million output tokens, and averages 87.7 across the index's benchmark suite.
It is a proprietary model under a proprietary licence. That determines whether you can self-host it, fine-tune it and keep data inside your own infrastructure.
Pricing and context
Claude Opus 4.5 costs $19.42 per million input tokens, $75.27 per million output tokens and $2.85 per million cached input tokens. The blended 3:1 figure is about $33.38 per million tokens.
The context window is 400,000 tokens and the maximum output is 4,096 tokens. If your prompts regularly exceed the context window, you need chunking or retrieval before price becomes the main issue.
Benchmark position
Claude Opus 4.5 averages 87.7 across the index's scored benchmarks, ranking #12 of 600. Its strongest relative result is LiveCodeBench.
Use the table below to see the full benchmark profile. A single strong score is less useful than a consistent profile across the benchmarks that resemble your task.
Alternatives
The closest models by average score are Claude Sonnet 4.5 Reasoning, GPT-5.1 Pro, Claude Opus 4.5 Max. Compare their prices before assuming the closest score is the best substitute; a small quality drop can cut unit cost substantially.
Claude Opus 4.5 benchmark profile
| Benchmark | Score | Rank | Percentile |
|---|---|---|---|
| MMLU-Pro | 87.0 | #33 | 95th |
| GPQA Diamond | 81.7 | #34 | 94th |
| SWE-bench Verified | 77.1 | #22 | 96th |
| HumanEval | 93.7 | #5 | 99th |
| MATH-500 | 93.7 | #8 | 99th |
| AIME 2025 | 89.8 | #7 | 99th |
| LiveCodeBench | 85.0 | #3 | 100th |
| IFEval | 92.5 | #29 | 95th |
Related
FAQ
Is Claude Opus 4.5 worth it?
Claude Opus 4.5 averages 87.7 and costs $19.42 per million input tokens. Whether it is worth it depends on whether your task benefits from its benchmark profile; test it against a cheaper alternative.
What is the most important factor in claude-opus-4-5?
Fit to the task beats raw benchmark rank. Define the failure modes, pick the benchmarks that resemble them, then test a small shortlist on your own examples.
How many models should I evaluate?
Three is usually enough: a quality candidate, a value candidate and a fallback. More candidates add work without changing the decision.
How do I control cost?
Compare blended 3:1 price, watch output tokens, use caching where available and route simple requests to a cheaper model.