Claude Sonnet 4.5 vs Gemini Robotics-ER 1.6 Preview
Claude Sonnet 4.5 (2025) and Gemini Robotics-ER 1.6 Preview (2026) are frontier-tier reasoning models from Anthropic and Google DeepMind. Claude Sonnet 4.5 ships a 200k-token context window, while Gemini Robotics-ER 1.6 Preview ships a 128k-token context window. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads. It focuses on practical selection signals rather than broad model-family marketing.
Gemini Robotics-ER 1.6 Preview is safer overall; choose Claude Sonnet 4.5 when long-context analysis matters.
Decision scorecard
Local evidence first| Signal | Claude Sonnet 4.5 | Gemini Robotics-ER 1.6 Preview |
|---|---|---|
| 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 | RAG, Agents, and Long context |
| Context window | 200k | 128k |
| Cheapest output | $15/1M tokens | $5/1M tokens |
| Provider routes | 8 tracked | 1 tracked |
| Shared benchmarks | 0 shared | 0 shared |
Decision tradeoffs
- Claude Sonnet 4.5 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- 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.
- Gemini Robotics-ER 1.6 Preview has the lower cheapest tracked output price at $5/1M tokens.
- Local decision data tags Gemini Robotics-ER 1.6 Preview for RAG, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Claude Sonnet 4.5
$6,150
Cheapest tracked route/tier: Microsoft Foundry
Gemini Robotics-ER 1.6 Preview
$2,050
Cheapest tracked route/tier: Google AI Studio
Estimated monthly gap: $4,100. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Claude Sonnet 4.5 and Gemini Robotics-ER 1.6 Preview; plan for SDK, billing, or endpoint changes.
- Gemini Robotics-ER 1.6 Preview is $10/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- No overlapping tracked provider route is sourced for Gemini Robotics-ER 1.6 Preview and Claude Sonnet 4.5; plan for SDK, billing, or endpoint changes.
- Claude Sonnet 4.5 is $10/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-09-29 | 2026-04-14 |
| Context window | 200k | 128k |
| Parameters | — | — |
| Architecture | Decoder Only | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | 2025-12 | - |
Pricing and availability
| Pricing attribute | Claude Sonnet 4.5 | Gemini Robotics-ER 1.6 Preview |
|---|---|---|
| Input price |
| $1/1M tokens |
| Output price |
| $5/1M tokens |
| Providers |
Capabilities
| Capability | Claude Sonnet 4.5 | Gemini Robotics-ER 1.6 Preview |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark scores are currently available for this pair.
Deep dive
The capability footprint is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, 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, while Gemini Robotics-ER 1.6 Preview lists $1/1M input and $5/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Gemini Robotics-ER 1.6 Preview 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 8 providers versus 1, so concentration risk also matters.
Choose Claude Sonnet 4.5 when long-context analysis, larger context windows, and broader provider choice are central to the workload. Choose Gemini Robotics-ER 1.6 Preview when vision-heavy evaluation 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 Robotics-ER 1.6 Preview?
Claude Sonnet 4.5 supports 200k tokens, while Gemini Robotics-ER 1.6 Preview supports 128k 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 Robotics-ER 1.6 Preview?
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. Gemini Robotics-ER 1.6 Preview lists $1/1M input and $5/1M output tokens on the cheapest tracked provider. 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 4.5 or Gemini Robotics-ER 1.6 Preview open source?
Claude Sonnet 4.5 is listed under Proprietary. Gemini Robotics-ER 1.6 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 4.5 or Gemini Robotics-ER 1.6 Preview?
Both Claude Sonnet 4.5 and Gemini Robotics-ER 1.6 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 4.5 or Gemini Robotics-ER 1.6 Preview?
Both Claude Sonnet 4.5 and Gemini Robotics-ER 1.6 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 4.5 and Gemini Robotics-ER 1.6 Preview?
Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. Gemini Robotics-ER 1.6 Preview is available on Google AI Studio. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.