Doubao Pro 256K vs Qwen3.5-Flash
Doubao Pro 256K (2024) and Qwen3.5-Flash (2026) are general-purpose language models from ByteDance and Alibaba. Doubao Pro 256K ships a 256k-token context window, while Qwen3.5-Flash ships a 1m-token context window. On pricing, Qwen3.5-Flash costs $0.07/1M input tokens versus $0.73/1M 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-Flash is ~950% cheaper at $0.07/1M; pay for Doubao Pro 256K only for provider fit.
Decision scorecard
Local evidence first| Signal | Doubao Pro 256K | Qwen3.5-Flash |
|---|---|---|
| Best for | general production evaluation | multimodal apps, long-context analysis, and provider-routed production |
| Decision fit | Long context | Long context, Vision, and Classification |
| Context window | 256k | 1m |
| Cheapest output | $1.32/1M tokens | $0.26/1M tokens |
| Provider routes | 1 tracked | 3 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Local decision data tags Doubao Pro 256K for Long context.
- Qwen3.5-Flash has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Qwen3.5-Flash has the lower cheapest tracked output price at $0.26/1M tokens.
- Qwen3.5-Flash has broader tracked provider coverage for fallback and procurement flexibility.
- Qwen3.5-Flash uniquely exposes Vision and Multimodal in local model data.
- Local decision data tags Qwen3.5-Flash for Long context, Vision, and Classification.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Doubao Pro 256K
$919
Cheapest tracked route/tier: Volcengine
Qwen3.5-Flash
$121
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $798. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- No overlapping tracked provider route is sourced for Doubao Pro 256K and Qwen3.5-Flash; plan for SDK, billing, or endpoint changes.
- Qwen3.5-Flash is $1.06/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Qwen3.5-Flash adds Vision and Multimodal in local capability data.
- No overlapping tracked provider route is sourced for Qwen3.5-Flash and Doubao Pro 256K; plan for SDK, billing, or endpoint changes.
- Doubao Pro 256K is $1.06/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Vision and Multimodal before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2024-05-15 | 2026-02-23 |
| Context window | 256k | 1m |
| Parameters | — | — |
| Architecture | decoder only | - |
| License | Proprietary | Apache 2.0(OSI) |
| Openness | Proprietary | Open source |
| Commercial use | Commercial use with conditions | Commercial use allowed |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Doubao Pro 256K | Qwen3.5-Flash |
|---|---|---|
| Input price | $0.73/1M tokens | $0.07/1M tokens |
| Output price | $1.32/1M tokens | $0.26/1M tokens |
| Providers |
Capabilities
| Capability | Doubao Pro 256K | Qwen3.5-Flash |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | Yes |
| Reasoning | No | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | No | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: Qwen3.5-Flash and multimodal input: Qwen3.5-Flash. Both models share the core language-model surface, 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, Doubao Pro 256K lists $0.73/1M input and $1.32/1M output tokens on the cheapest tracked provider, while Qwen3.5-Flash lists $0.07/1M input and $0.26/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Qwen3.5-Flash lower by about $0.78 per million blended tokens. Availability is 1 providers versus 3, so concentration risk also matters.
Choose Doubao Pro 256K when provider fit are central to the workload. Choose Qwen3.5-Flash 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. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Which has a larger context window, Doubao Pro 256K or Qwen3.5-Flash?
Qwen3.5-Flash supports 1m tokens, while Doubao Pro 256K supports 256k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Doubao Pro 256K or Qwen3.5-Flash?
Qwen3.5-Flash is cheaper on tracked token pricing. Doubao Pro 256K costs $0.73/1M input and $1.32/1M output tokens. Qwen3.5-Flash costs $0.07/1M input and $0.26/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Doubao Pro 256K or Qwen3.5-Flash open source?
Doubao Pro 256K is listed under Proprietary. Qwen3.5-Flash 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, Doubao Pro 256K or Qwen3.5-Flash?
Qwen3.5-Flash 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, Doubao Pro 256K or Qwen3.5-Flash?
Qwen3.5-Flash 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 Doubao Pro 256K and Qwen3.5-Flash?
Doubao Pro 256K is available on Volcengine. Qwen3.5-Flash is available on Alibaba Cloud PAI-EAS, OpenRouter, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-04. Data sourced from public model cards and provider documentation.