Claude Sonnet 4.5 vs Gemini 2.5 Pro
Claude Sonnet 4.5 (2025) and Gemini 2.5 Pro (2025) are frontier reasoning models from Anthropic and Google DeepMind. Claude Sonnet 4.5 ships a 200K-token context window, while Gemini 2.5 Pro ships a 1M-token context window. On MMLU PRO, Gemini 2.5 Pro leads by a hair. On pricing, Gemini 2.5 Pro costs $1.25/1M input tokens versus $3/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
Gemini 2.5 Pro is ~140% cheaper at $1.25/1M; pay for Claude Sonnet 4.5 only for reasoning depth.
Specs
| Released | 2025-09-29 | 2025-06-17 |
| Context window | 200K | 1M |
| Parameters | — | — |
| Architecture | decoder only | decoder only |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-12 | 2025-01 |
Pricing and availability
| Claude Sonnet 4.5 | Gemini 2.5 Pro | |
|---|---|---|
| Input price | $3/1M tokens | $1.25/1M tokens |
| Output price | $15/1M tokens | $10/1M tokens |
| Providers |
Capabilities
| Claude Sonnet 4.5 | Gemini 2.5 Pro | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | Claude Sonnet 4.5 | Gemini 2.5 Pro |
|---|---|---|
| MMLU PRO | 86.0 | 86.2 |
Deep dive
On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.5 at 86 and Gemini 2.5 Pro at 86.2, with Gemini 2.5 Pro ahead by 0.2 points. The largest visible gap is 0.2 points on MMLU PRO, 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 Sonnet 4.5 and code execution: Gemini 2.5 Pro. 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 Sonnet 4.5 lists $3/1M input and $15/1M output tokens, while Gemini 2.5 Pro lists $1.25/1M input and $10/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Gemini 2.5 Pro lower by about $2.72 per million blended tokens. Availability is 8 providers versus 3, so concentration risk also matters.
Choose Claude Sonnet 4.5 when reasoning depth and broader provider choice are central to the workload. Choose Gemini 2.5 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 Sonnet 4.5 or Gemini 2.5 Pro?
Gemini 2.5 Pro supports 1M 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 Sonnet 4.5 or Gemini 2.5 Pro?
Gemini 2.5 Pro is cheaper on tracked token pricing. Claude Sonnet 4.5 costs $3/1M input and $15/1M output tokens. Gemini 2.5 Pro costs $1.25/1M input and $10/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Claude Sonnet 4.5 or Gemini 2.5 Pro open source?
Claude Sonnet 4.5 is listed under Proprietary. Gemini 2.5 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 Sonnet 4.5 or Gemini 2.5 Pro?
Both Claude Sonnet 4.5 and Gemini 2.5 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 Sonnet 4.5 or Gemini 2.5 Pro?
Both Claude Sonnet 4.5 and Gemini 2.5 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 Sonnet 4.5 and Gemini 2.5 Pro?
Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. Gemini 2.5 Pro is available on Google AI Studio, GCP Vertex AI, and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.