Claude Sonnet 4.6 vs Gemini 3.1 Pro Preview
Claude Sonnet 4.6 (2026) and Gemini 3.1 Pro Preview (2026) are frontier reasoning models from Anthropic and Google DeepMind. Claude Sonnet 4.6 ships a 1m-token context window, while Gemini 3.1 Pro Preview ships a 1m-token context window. On MMLU PRO, Gemini 3.1 Pro Preview leads by 3.7 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Gemini 3.1 Pro Preview is safer overall; choose Claude Sonnet 4.6 when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | Claude Sonnet 4.6 | Gemini 3.1 Pro Preview |
|---|---|---|
| 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 | 1m | 1m |
| Cheapest output | $15/1M tokens | $12/1M tokens |
| Provider routes | 6 tracked | 5 tracked |
| Shared benchmarks | 14 shared | MMLU PRO leader |
Decision tradeoffs
- Claude Sonnet 4.6 holds a shared-benchmark lead on HumanEval, ahead by 4 points.
- Claude Sonnet 4.6 has broader tracked provider coverage for fallback and procurement flexibility.
- Claude Sonnet 4.6 uniquely exposes Reasoning, Computer use, and Parallel agents in local model data.
- Local decision data tags Claude Sonnet 4.6 for Coding, RAG, and Agents.
- Gemini 3.1 Pro Preview holds a shared-benchmark lead on MMLU PRO, ahead by 3.7 points.
- Gemini 3.1 Pro Preview has the lower cheapest tracked output price at $12/1M tokens.
- Local decision data tags Gemini 3.1 Pro Preview 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 Sonnet 4.6
$6,150
Cheapest tracked route/tier: OpenRouter
Gemini 3.1 Pro Preview
$4,600
Cheapest tracked route/tier: Google AI Studio
Estimated monthly gap: $1,550. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on GCP Vertex AI, OpenRouter, and Vercel AI Gateway; start route-level A/B tests there.
- Gemini 3.1 Pro Preview is $3/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning, Computer use, and Parallel agents before moving production traffic.
- Provider overlap exists on OpenRouter, GCP Vertex AI, and Vercel AI Gateway; start route-level A/B tests there.
- Claude Sonnet 4.6 is $3/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Sonnet 4.6 adds Reasoning, Computer use, and Parallel agents in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-02-17 | 2026-02-19 |
| Context window | 1m | 1m |
| 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 | 2025-08 | 2025-01 |
Pricing and availability
| Pricing attribute | Claude Sonnet 4.6 | Gemini 3.1 Pro Preview |
|---|---|---|
| Input price | $3/1M tokens |
|
| Output price | $15/1M tokens |
|
| Providers |
Capabilities
| Capability | Claude Sonnet 4.6 | Gemini 3.1 Pro Preview |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | No |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | Yes |
| IDE integration | No | No |
| Computer use | Yes | No |
| Parallel agents | Yes | No |
Benchmarks
| Benchmark | Claude Sonnet 4.6 | Gemini 3.1 Pro Preview |
|---|---|---|
| MMLU PRO | 87.3 | 91.0 |
| SWE-bench Verified | 79.6 | 80.6 |
| Google-Proof Q&A | 89.9 | 94.3 |
| AIME 2025 | 94.0 | 95.0 |
| LiveCodeBench | 80.0 | 91.7 |
| Humanity's Last Exam | 33.2 | 51.4 |
| HumanEval | 98.0 | 94.0 |
| Chatbot Arena | 1459.0 | 1493.0 |
| ARC-AGI-2 | 58.3 | 77.1 |
| MultiChallenge | 57.1 | 71.4 |
| MMMU Pro | 75.6 | 88.2 |
| τ-bench | 87.5 | 76.5 |
| Massive Multitask Language Understanding | 89.3 | 98.0 |
| MCP-Atlas | 61.3 | 69.2 |
Deep dive
On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.6 at 87.3 and Gemini 3.1 Pro Preview at 91.0, with Gemini 3.1 Pro Preview ahead by 3.7 points; SWE-bench Verified has Claude Sonnet 4.6 at 79.6 and Gemini 3.1 Pro Preview at 80.6, with Gemini 3.1 Pro Preview ahead by 1 points; Google-Proof Q&A has Claude Sonnet 4.6 at 89.9 and Gemini 3.1 Pro Preview at 94.3, with Gemini 3.1 Pro Preview ahead by 4.4 points. The largest visible gap is 4.4 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 Sonnet 4.6. 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 4.6 lists $3/1M input and $15/1M output tokens on the cheapest tracked provider, while Gemini 3.1 Pro Preview lists tiered pricing: 0-200,001t is $2/1M input and $12/1M output; 200,001t+ is $4/1M input and $18/1M output. A 70/30 input-output blend puts Gemini 3.1 Pro Preview lower by about $1.60 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 5, so concentration risk also matters.
Choose Claude Sonnet 4.6 when coding workflow support and broader provider choice are central to the workload. Choose Gemini 3.1 Pro Preview when coding workflow support and lower cheapest-tier 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 4.6 or Gemini 3.1 Pro Preview?
Claude Sonnet 4.6 supports 1m tokens, while Gemini 3.1 Pro Preview supports 1m 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 4.6 or Gemini 3.1 Pro Preview?
Claude Sonnet 4.6 lists $3/1M input and $15/1M output tokens on the cheapest tracked provider. Gemini 3.1 Pro Preview lists tiered pricing: 0-200,001t is $2/1M input and $12/1M output; 200,001t+ is $4/1M input and $18/1M 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 Sonnet 4.6 or Gemini 3.1 Pro Preview open source?
Claude Sonnet 4.6 is listed under Proprietary. Gemini 3.1 Pro Preview 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 4.6 or Gemini 3.1 Pro Preview?
Both Claude Sonnet 4.6 and Gemini 3.1 Pro Preview 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 4.6 or Gemini 3.1 Pro Preview?
Both Claude Sonnet 4.6 and Gemini 3.1 Pro Preview 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 4.6 and Gemini 3.1 Pro Preview?
Claude Sonnet 4.6 is available on OpenRouter, Anthropic, AWS Bedrock, GCP Vertex AI, and Microsoft Foundry. Gemini 3.1 Pro Preview is available on Google AI Studio, GCP Vertex AI, OpenRouter, Replicate API, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.