Claude Opus 4.5 vs Claude Sonnet 4.5
Claude Opus 4.5 (2025) and Claude Sonnet 4.5 (2025) are frontier-tier reasoning models from Anthropic. Claude Opus 4.5 ships a 200k-token context window, while Claude Sonnet 4.5 ships a 200k-token context window. On MMLU PRO, Claude Opus 4.5 leads by 2.9 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Claude Opus 4.5 is safer overall; choose Claude Sonnet 4.5 when vision-heavy evaluation matters.
Decision scorecard
Local evidence first| Signal | Claude Opus 4.5 | Claude Sonnet 4.5 |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200k | 200k |
| Cheapest output | $25/1M tokens | $15/1M tokens |
| Provider routes | 6 tracked | 8 tracked |
| Shared benchmarks | MMLU PRO leader | 6 shared |
Decision tradeoffs
- Claude Opus 4.5 holds a shared-benchmark lead on MMLU PRO, ahead by 2.9 points.
- Claude Opus 4.5 uniquely exposes Code execution in local model data.
- Local decision data tags Claude Opus 4.5 for Coding, RAG, and Agents.
- Claude Sonnet 4.5 has the lower cheapest tracked output price at $15/1M tokens.
- Claude Sonnet 4.5 has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Opus 4.5
$10,250
Cheapest tracked route/tier: Microsoft Foundry
Claude Sonnet 4.5
$6,150
Cheapest tracked route/tier: Microsoft Foundry
Estimated monthly gap: $4,100. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Microsoft Foundry, Anthropic, and GCP Vertex AI; start route-level A/B tests there.
- Claude Sonnet 4.5 is $10/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Code execution before moving production traffic.
- Provider overlap exists on Microsoft Foundry, Anthropic, and GCP Vertex AI; start route-level A/B tests there.
- Claude Opus 4.5 is $10/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Opus 4.5 adds Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-01 | 2025-09-29 |
| Context window | 200k | 200k |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Weights | Not released | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-12 | 2025-12 |
Pricing and availability
| Pricing attribute | Claude Opus 4.5 | Claude Sonnet 4.5 |
|---|---|---|
| Input price | $5/1M tokens |
|
| Output price | $25/1M tokens |
|
| Providers |
Capabilities
| Capability | Claude Opus 4.5 | Claude Sonnet 4.5 |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Opus 4.5 | Claude Sonnet 4.5 |
|---|---|---|
| MMLU PRO | 88.9 | 86.0 |
| SWE-bench Verified | 80.9 | 77.2 |
| Google-Proof Q&A | 87.0 | 83.4 |
| Massive Multi-discipline Multimodal Understanding | 80.7 | 77.8 |
| MMMU Pro | 73.9 | 68.9 |
| BFCL | 77.5 | 73.2 |
Continue comparing
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- Claude Sonnet 4.5 vs Kimi K2.6
- Claude Sonnet 4.5 vs Qwen3.6-27B
- Claude Sonnet 4.5 vs GPT-5.5
- Claude Opus 4.5 vs DeepSeek V4 Pro
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Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.