o3 vs Qwen3.5-35B-A3B
o3 (2025) and Qwen3.5-35B-A3B (2026) are frontier-tier reasoning models from OpenAI and Alibaba. o3 ships a 128K-token context window, while Qwen3.5-35B-A3B ships a 262K-token context window. On Google-Proof Q&A, o3 leads by 3.2 pts. On pricing, Qwen3.5-35B-A3B costs $0.16/1M input tokens versus $1/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.
Qwen3.5-35B-A3B is ~515% cheaper at $0.16/1M; pay for o3 only for coding workflow support.
Specs
| Released | 2025-03-31 | 2026-02-24 |
| Context window | 128K | 262K |
| Parameters | — | 35B |
| Architecture | decoder only | mixture of experts |
| License | Unknown | Apache 2.0 |
| Knowledge cutoff | - | - |
Pricing and availability
| o3 | Qwen3.5-35B-A3B | |
|---|---|---|
| Input price | $1/1M tokens | $0.16/1M tokens |
| Output price | $4/1M tokens | $1.3/1M tokens |
| Providers |
Capabilities
| o3 | Qwen3.5-35B-A3B | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | o3 | Qwen3.5-35B-A3B |
|---|---|---|
| Google-Proof Q&A | 87.7 | 84.5 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has o3 at 87.7 and Qwen3.5-35B-A3B at 84.5, with o3 ahead by 3.2 points. The largest visible gap is 3.2 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 function calling: Qwen3.5-35B-A3B, tool use: Qwen3.5-35B-A3B, and code execution: o3. Both models share reasoning mode 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, o3 lists $1/1M input and $4/1M output tokens, while Qwen3.5-35B-A3B lists $0.16/1M input and $1.3/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Qwen3.5-35B-A3B lower by about $1.4 per million blended tokens. Availability is 3 providers versus 1, so concentration risk also matters.
Choose o3 when coding workflow support 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, o3 or Qwen3.5-35B-A3B?
Qwen3.5-35B-A3B supports 262K tokens, while o3 supports 128K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is cheaper, o3 or Qwen3.5-35B-A3B?
Qwen3.5-35B-A3B is cheaper on tracked token pricing. o3 costs $1/1M input and $4/1M output tokens. Qwen3.5-35B-A3B costs $0.16/1M input and $1.3/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is o3 or Qwen3.5-35B-A3B open source?
o3 is listed under Unknown. 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 reasoning mode, o3 or Qwen3.5-35B-A3B?
Both o3 and Qwen3.5-35B-A3B expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for function calling, o3 or Qwen3.5-35B-A3B?
Qwen3.5-35B-A3B has the clearer documented function calling signal in this comparison. If function calling is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Where can I run o3 and Qwen3.5-35B-A3B?
o3 is available on OpenAI API, OpenRouter, and OpenAI Batch API. Qwen3.5-35B-A3B is available on OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.