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 rows |
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 procurement 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 |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| 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 |
| Function calling | Yes | Yes |
| 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 |
Deep dive
On shared benchmark coverage, MMLU PRO has Claude Opus 4.5 at 88.9 and Claude Sonnet 4.5 at 86, with Claude Opus 4.5 ahead by 2.9 points; SWE-bench Verified has Claude Opus 4.5 at 80.9 and Claude Sonnet 4.5 at 77.2, with Claude Opus 4.5 ahead by 3.7 points; Google-Proof Q&A has Claude Opus 4.5 at 87 and Claude Sonnet 4.5 at 83.4, with Claude Opus 4.5 ahead by 3.6 points. The largest visible gap is 3.7 points on SWE-bench Verified, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on code execution: Claude Opus 4.5. Both models share vision, multimodal input, reasoning mode, and function calling, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, Claude Opus 4.5 lists $5/1M input and $25/1M output tokens on the cheapest tracked provider, while Claude Sonnet 4.5 lists tiered pricing: 0-200,001t is $3/1M input and $15/1M output; 200,001t+ is $6/1M input and $22.50/1M output. A 70/30 input-output blend puts Claude Sonnet 4.5 lower by about $4.40 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 6 providers versus 8, so concentration risk also matters.
Choose Claude Opus 4.5 when coding workflow support are central to the workload. Choose Claude Sonnet 4.5 when vision-heavy evaluation, lower cheapest-tier input-token cost, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Claude Opus 4.5 or Claude Sonnet 4.5?
Claude Opus 4.5 supports 200k tokens, while Claude Sonnet 4.5 supports 200k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Claude Opus 4.5 or Claude Sonnet 4.5?
Claude Opus 4.5 lists $5/1M input and $25/1M output tokens on the cheapest tracked provider. Claude Sonnet 4.5 lists tiered pricing: 0-200,001t is $3/1M input and $15/1M output; 200,001t+ is $6/1M input and $22.50/1M output. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.
Is Claude Opus 4.5 or Claude Sonnet 4.5 open source?
Claude Opus 4.5 is listed under Proprietary. Claude Sonnet 4.5 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, Claude Opus 4.5 or Claude Sonnet 4.5?
Both Claude Opus 4.5 and Claude Sonnet 4.5 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Which is better for multimodal input, Claude Opus 4.5 or Claude Sonnet 4.5?
Both Claude Opus 4.5 and Claude Sonnet 4.5 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Claude Opus 4.5 and Claude Sonnet 4.5?
Claude Opus 4.5 is available on Microsoft Foundry, Anthropic, GCP Vertex AI, AWS Bedrock, and OpenRouter. Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.