Claude Opus 4.5 vs Gemini 3 Pro
Claude Opus 4.5 (2025) and Gemini 3 Pro (2025) are frontier reasoning models from Anthropic and Google DeepMind. Claude Opus 4.5 ships a 200k-token context window, while Gemini 3 Pro ships a 1m-token context window. On MMLU PRO, Gemini 3 Pro 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.
Gemini 3 Pro is ~300% cheaper at $1.25/1M; pay for Claude Opus 4.5 only for coding workflow support.
Decision scorecard
Local evidence first| Signal | Claude Opus 4.5 | Gemini 3 Pro |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | multimodal apps, tool-calling agents, and long-context analysis |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200k | 1m |
| Cheapest output | $25/1M tokens | $5/1M tokens |
| Provider routes | 6 tracked | 2 tracked |
| Shared benchmarks | 7 rows | MMLU PRO leader |
Decision tradeoffs
- Claude Opus 4.5 leads the largest shared benchmark signal on SWE-bench Verified by 4.7 points.
- Claude Opus 4.5 has broader tracked provider coverage for fallback and procurement flexibility.
- Claude Opus 4.5 uniquely exposes Reasoning and Structured outputs in local model data.
- Local decision data tags Claude Opus 4.5 for Coding, RAG, and Agents.
- Gemini 3 Pro leads the largest shared benchmark signal on MMLU PRO by 2.9 points.
- Gemini 3 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Gemini 3 Pro has the lower cheapest tracked output price at $5/1M tokens.
- Local decision data tags Gemini 3 Pro 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
Gemini 3 Pro
$2,250
Cheapest tracked route/tier: GCP Vertex AI
Estimated monthly gap: $8,000. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on GCP Vertex AI; start route-level A/B tests there.
- Gemini 3 Pro is $20/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning and Structured outputs before moving production traffic.
- Provider overlap exists on GCP Vertex AI; start route-level A/B tests there.
- Claude Opus 4.5 is $20/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Opus 4.5 adds Reasoning and Structured outputs in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-11-01 | 2025-12-11 |
| Context window | 200k | 1m |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-12 | 2025-01 |
Pricing and availability
| Pricing attribute | Claude Opus 4.5 | Gemini 3 Pro |
|---|---|---|
| Input price | $5/1M tokens | $1.25/1M tokens |
| Output price | $25/1M tokens | $5/1M tokens |
| Providers |
Capabilities
| Capability | Claude Opus 4.5 | Gemini 3 Pro |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | No |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | No |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Claude Opus 4.5 | Gemini 3 Pro |
|---|---|---|
| MMLU PRO | 88.9 | 91.8 |
| SWE-bench Verified | 80.9 | 76.2 |
| Google-Proof Q&A | 87.0 | 91.9 |
| Chatbot Arena | 1466.0 | 1486.0 |
| BFCL | 77.5 | 72.5 |
| SWE-bench Pro | 41.8 | 42.5 |
| Massive Multi-discipline Multimodal Understanding | 80.7 | 81.0 |
Deep dive
On shared benchmark coverage, MMLU PRO has Claude Opus 4.5 at 88.9 and Gemini 3 Pro at 91.8, with Gemini 3 Pro ahead by 2.9 points; SWE-bench Verified has Claude Opus 4.5 at 80.9 and Gemini 3 Pro at 76.2, with Claude Opus 4.5 ahead by 4.7 points; Google-Proof Q&A has Claude Opus 4.5 at 87 and Gemini 3 Pro at 91.9, with Gemini 3 Pro ahead by 4.9 points. The largest visible gap is 4.9 points on Google-Proof Q&A, 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 reasoning mode: Claude Opus 4.5 and structured outputs: Claude Opus 4.5. Both models share vision, multimodal input, function calling, and tool use, 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 Gemini 3 Pro lists $1.25/1M input and $5/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Gemini 3 Pro lower by about $8.63 per million blended tokens. Availability is 6 providers versus 2, so concentration risk also matters.
Choose Claude Opus 4.5 when coding workflow support and broader provider choice are central to the workload. Choose Gemini 3 Pro when coding workflow support, larger context windows, and lower input-token cost 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 Gemini 3 Pro?
Gemini 3 Pro supports 1m tokens, while Claude Opus 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 Gemini 3 Pro?
Gemini 3 Pro is cheaper on tracked token pricing. Claude Opus 4.5 costs $5/1M input and $25/1M output tokens. Gemini 3 Pro costs $1.25/1M input and $5/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Claude Opus 4.5 or Gemini 3 Pro open source?
Claude Opus 4.5 is listed under Proprietary. Gemini 3 Pro 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 Gemini 3 Pro?
Both Claude Opus 4.5 and Gemini 3 Pro 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 Gemini 3 Pro?
Both Claude Opus 4.5 and Gemini 3 Pro 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 Gemini 3 Pro?
Claude Opus 4.5 is available on Microsoft Foundry, Anthropic, GCP Vertex AI, AWS Bedrock, and OpenRouter. Gemini 3 Pro is available on Replicate API and GCP Vertex AI. 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.