LLM Reference

Doubao Pro 256K vs Qwen3.5-27B

Doubao Pro 256K (2024) and Qwen3.5-27B (2026) are frontier reasoning models from ByteDance and Alibaba. Doubao Pro 256K ships a 256k-token context window, while Qwen3.5-27B ships a 262k-token context window. On pricing, Qwen3.5-27B costs $0.20/1M 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.

Qwen3.5-27B is ~277% cheaper at $0.20/1M; pay for Doubao Pro 256K only for provider fit.

Decision scorecard

Local evidence first
SignalDoubao Pro 256KQwen3.5-27B
Best forgeneral production evaluationreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitLong contextCoding, RAG, and Agents
Context window256k262k
Cheapest output$1.32/1M tokens$1.56/1M tokens
Provider routes1 tracked4 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose Doubao Pro 256K when...
  • Doubao Pro 256K has the lower cheapest tracked output price at $1.32/1M tokens.
  • Local decision data tags Doubao Pro 256K for Long context.
Choose Qwen3.5-27B when...
  • Qwen3.5-27B has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Qwen3.5-27B has broader tracked provider coverage for fallback and procurement flexibility.
  • Qwen3.5-27B uniquely exposes Vision, Multimodal, and Reasoning in local model data.
  • Local decision data tags Qwen3.5-27B 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.

Lower estimate Qwen3.5-27B

Doubao Pro 256K

$919

Cheapest tracked route/tier: Volcengine

Qwen3.5-27B

$546

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $373. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Doubao Pro 256K -> Qwen3.5-27B
  • No overlapping tracked provider route is sourced for Doubao Pro 256K and Qwen3.5-27B; plan for SDK, billing, or endpoint changes.
  • Qwen3.5-27B is $0.24/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Qwen3.5-27B adds Vision, Multimodal, and Reasoning in local capability data.
Qwen3.5-27B -> Doubao Pro 256K
  • No overlapping tracked provider route is sourced for Qwen3.5-27B and Doubao Pro 256K; plan for SDK, billing, or endpoint changes.
  • Doubao Pro 256K is $0.24/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.

Specs

Specification
Released2024-05-152026-02-24
Context window256k262k
Parameters27B
Architecturedecoder onlydecoder only
LicenseProprietaryApache 2.0(OSI)
OpennessProprietaryOpen source
Commercial useCommercial use with conditionsCommercial use allowed
Knowledge cutoff--

Pricing and availability

Pricing attributeDoubao Pro 256KQwen3.5-27B
Input price$0.73/1M tokens$0.20/1M tokens
Output price$1.32/1M tokens$1.56/1M tokens
Providers

Capabilities

CapabilityDoubao Pro 256KQwen3.5-27B
VisionNoYes
MultimodalNoYes
ReasoningNoYes
Function callingNoYes
Tool useNoYes
Structured outputsNoYes
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

No shared benchmark rows are currently sourced for this pair.

Deep dive

The capability footprint differs most on vision: Qwen3.5-27B, multimodal input: Qwen3.5-27B, reasoning mode: Qwen3.5-27B, function calling: Qwen3.5-27B, tool use: Qwen3.5-27B, and structured outputs: Qwen3.5-27B. 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 Qwen3.5-27B lists $0.20/1M input and $1.56/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Qwen3.5-27B lower by about $0.31 per million blended tokens. Availability is 1 providers versus 4, so concentration risk also matters.

Choose Doubao Pro 256K when provider fit are central to the workload. Choose Qwen3.5-27B when reasoning depth, 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.

FAQ

Which has a larger context window, Doubao Pro 256K or Qwen3.5-27B?

Qwen3.5-27B supports 262k 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 Qwen3.5-27B?

Qwen3.5-27B is cheaper on tracked token pricing. Doubao Pro 256K costs $0.73/1M input and $1.32/1M output tokens. Qwen3.5-27B costs $0.20/1M input and $1.56/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Doubao Pro 256K or Qwen3.5-27B open source?

Doubao Pro 256K is listed under Proprietary. Qwen3.5-27B 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 Qwen3.5-27B?

Qwen3.5-27B 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 Qwen3.5-27B?

Qwen3.5-27B 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 Qwen3.5-27B?

Doubao Pro 256K is available on Volcengine. Qwen3.5-27B is available on DeepInfra, OpenRouter, Alibaba Cloud PAI-EAS, and Novita AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

Continue comparing

Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.