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 200k-token context window, while Qwen3.5-35B-A3B ships a 262k-token context window. On SWE-bench Verified, o3 leads by 2.5 pts. On pricing, Qwen3.5-35B-A3B costs $0.14/1M input tokens versus $2/1M for the alternative. 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 ~1339% cheaper at $0.14/1M; pay for o3 only for coding workflow support.
Decision scorecard
Local evidence first| Signal | o3 | 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 | $8/1M tokens | $1/1M tokens |
| Provider routes | 3 tracked | 2 tracked |
| Shared benchmarks | SWE-bench Verified leader | 5 rows |
Decision tradeoffs
- o3 holds a shared-benchmark lead on SWE-bench Verified, ahead by 2.5 points.
- o3 has broader tracked provider coverage for fallback and procurement flexibility.
- o3 uniquely exposes Vision, Multimodal, and Code execution in local model data.
- Local decision data tags o3 for Coding, RAG, and Agents.
- Qwen3.5-35B-A3B holds a shared-benchmark lead on Humanity's Last Exam, ahead by 2.1 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.
o3
$3,600
Cheapest tracked route/tier: OpenAI API
Qwen3.5-35B-A3B
$361
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $3,239. 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 $7/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Code execution before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- o3 is $7/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- o3 adds Vision, Multimodal, and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-04-16 | 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 | 2024-06 | - |
Pricing and availability
| Pricing attribute | o3 | Qwen3.5-35B-A3B |
|---|---|---|
| Input price | $2/1M tokens | $0.14/1M tokens |
| Output price | $8/1M tokens | $1/1M tokens |
| Providers |
Capabilities
| Capability | o3 | 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 | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | o3 | Qwen3.5-35B-A3B |
|---|---|---|
| SWE-bench Verified | 71.7 | 69.2 |
| Google-Proof Q&A | 87.7 | 84.5 |
| LiveCodeBench | 85.5 | 74.6 |
| Humanity's Last Exam | 20.3 | 22.4 |
| MMMU Pro | 76.4 | 75.1 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has o3 at 71.7 and Qwen3.5-35B-A3B at 69.2, with o3 ahead by 2.5 points; Google-Proof Q&A has o3 at 87.7 and Qwen3.5-35B-A3B at 84.5, with o3 ahead by 3.2 points; LiveCodeBench has o3 at 85.5 and Qwen3.5-35B-A3B at 74.6, with o3 ahead by 10.9 points. The largest visible gap is 10.9 points on LiveCodeBench, 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: o3, multimodal input: o3, and code execution: o3. 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, o3 lists $2/1M input and $8/1M output tokens on the cheapest tracked provider, 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 $3.40 per million blended tokens. Availability is 3 providers versus 2, 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 200k 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 $2/1M input and $8/1M output tokens. Qwen3.5-35B-A3B costs $0.14/1M input and $1/1M 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 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, o3 or Qwen3.5-35B-A3B?
o3 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. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, o3 or Qwen3.5-35B-A3B?
o3 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 o3 and Qwen3.5-35B-A3B?
o3 is available on OpenAI API, OpenRouter, and Vercel AI Gateway. Qwen3.5-35B-A3B is available on OpenRouter and Novita AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-08. Data sourced from public model cards and provider documentation.