Claude Sonnet 4.5 vs Qwen3.5-35B-A3B
Claude Sonnet 4.5 (2025) and Qwen3.5-35B-A3B (2026) are frontier-tier reasoning models from Anthropic and Alibaba. Claude Sonnet 4.5 ships a 200k-token context window, while Qwen3.5-35B-A3B ships a 262k-token context window. On MMLU PRO, Claude Sonnet 4.5 leads by 0.7 pts. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Qwen3.5-35B-A3B is safer overall; choose Claude Sonnet 4.5 when vision-heavy evaluation matters.
Decision scorecard
Local evidence first| Signal | Claude Sonnet 4.5 | Qwen3.5-35B-A3B |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, tool-calling agents, and provider-routed production |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 200k | 262k |
| Cheapest output | $15/1M tokens | $1/1M tokens |
| Provider routes | 8 tracked | 2 tracked |
| Shared benchmarks | MMLU PRO leader | 4 rows |
Decision tradeoffs
- Claude Sonnet 4.5 holds a shared-benchmark lead on MMLU PRO, ahead by 0.7 points.
- Claude Sonnet 4.5 has broader tracked provider coverage for fallback and procurement flexibility.
- Claude Sonnet 4.5 uniquely exposes Vision and Multimodal in local model data.
- Local decision data tags Claude Sonnet 4.5 for Coding, RAG, and Agents.
- Qwen3.5-35B-A3B holds a shared-benchmark lead on Google-Proof Q&A, ahead by 1.1 points.
- Qwen3.5-35B-A3B has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Qwen3.5-35B-A3B has the lower cheapest tracked output price at $1/1M tokens.
- Local decision data tags Qwen3.5-35B-A3B 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 4.5
$6,150
Cheapest tracked route/tier: Microsoft Foundry
Qwen3.5-35B-A3B
$361
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $5,789. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Qwen3.5-35B-A3B is $14/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision and Multimodal before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Claude Sonnet 4.5 is $14/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Claude Sonnet 4.5 adds Vision and Multimodal in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-09-29 | 2026-02-24 |
| Context window | 200k | 262k |
| Parameters | — | 35B |
| Architecture | decoder only | mixture of experts |
| License | Proprietary | Apache 2.0(OSI) |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use with conditions | Commercial use allowed |
| Knowledge cutoff | 2025-12 | - |
Pricing and availability
| Pricing attribute | Claude Sonnet 4.5 | Qwen3.5-35B-A3B |
|---|---|---|
| Input price |
| $0.14/1M tokens |
| Output price |
| $1/1M tokens |
| Providers |
Capabilities
| Capability | Claude Sonnet 4.5 | Qwen3.5-35B-A3B |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| 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
| Benchmark | Claude Sonnet 4.5 | Qwen3.5-35B-A3B |
|---|---|---|
| MMLU PRO | 86.0 | 85.3 |
| SWE-bench Verified | 77.2 | 69.2 |
| Google-Proof Q&A | 83.4 | 84.5 |
| MMMU Pro | 68.9 | 75.1 |
Deep dive
On shared benchmark coverage, MMLU PRO has Claude Sonnet 4.5 at 86 and Qwen3.5-35B-A3B at 85.3, with Claude Sonnet 4.5 ahead by 0.7 points; SWE-bench Verified has Claude Sonnet 4.5 at 77.2 and Qwen3.5-35B-A3B at 69.2, with Claude Sonnet 4.5 ahead by 8 points; Google-Proof Q&A has Claude Sonnet 4.5 at 83.4 and Qwen3.5-35B-A3B at 84.5, with Qwen3.5-35B-A3B ahead by 1.1 points. The largest visible gap is 8 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 vision: Claude Sonnet 4.5 and multimodal input: Claude Sonnet 4.5. Both models share reasoning mode, function calling, tool use, and structured outputs, 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 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 Qwen3.5-35B-A3B lists $0.14/1M input and $1/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Qwen3.5-35B-A3B lower by about $6.20 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 2, so concentration risk also matters.
Choose Claude Sonnet 4.5 when vision-heavy evaluation and broader provider choice are central to the workload. Choose Qwen3.5-35B-A3B when long-context analysis, 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 Qwen3.5-35B-A3B?
Qwen3.5-35B-A3B supports 262k 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 Qwen3.5-35B-A3B?
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. Qwen3.5-35B-A3B lists $0.14/1M input and $1/1M 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 Qwen3.5-35B-A3B open source?
Claude Sonnet 4.5 is listed under Proprietary. Qwen3.5-35B-A3B is listed under Apache 2.0. 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 Qwen3.5-35B-A3B?
Claude Sonnet 4.5 has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for multimodal input, Claude Sonnet 4.5 or Qwen3.5-35B-A3B?
Claude Sonnet 4.5 has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run Claude Sonnet 4.5 and Qwen3.5-35B-A3B?
Claude Sonnet 4.5 is available on Microsoft Foundry, Anthropic, Snowflake Cortex, GCP Vertex AI, and AWS Bedrock. Qwen3.5-35B-A3B is available on OpenRouter and Novita 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.