LLM Reference

Qwen3.5-397B-A17B vs Qwen3.5-Flash

Qwen3.5-397B-A17B (2026) and Qwen3.5-Flash (2026) are frontier reasoning models from Alibaba. Qwen3.5-397B-A17B ships a 262k-token context window, while Qwen3.5-Flash ships a 1m-token context window. On MMLU PRO, Qwen3.5-397B-A17B leads by 2.5 pts. On pricing, Qwen3.5-Flash costs $0.07/1M input tokens versus $0.39/1M 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 ~457% cheaper at $0.07/1M; pay for Qwen3.5-397B-A17B only for reasoning depth.

Decision scorecard

Local evidence first
SignalQwen3.5-397B-A17BQwen3.5-Flash
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsmultimodal apps, long-context analysis, and provider-routed production
Decision fitCoding, RAG, and AgentsLong context, Vision, and Classification
Context window262k1m
Cheapest output$2.34/1M tokens$0.26/1M tokens
Provider routes4 tracked3 tracked
Shared benchmarksMMLU PRO leader2 shared

Decision tradeoffs

Choose Qwen3.5-397B-A17B when...
  • Qwen3.5-397B-A17B holds a shared-benchmark lead on MMLU PRO, ahead by 2.5 points.
  • Qwen3.5-397B-A17B has broader tracked provider coverage for fallback and route flexibility.
  • Qwen3.5-397B-A17B uniquely exposes Reasoning, JSON / Tool use, and Structured outputs in local model data.
  • Local decision data tags Qwen3.5-397B-A17B for Coding, RAG, and Agents.
Choose Qwen3.5-Flash when...
  • 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.
  • 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.

Lower estimate Qwen3.5-Flash

Qwen3.5-397B-A17B

$897

Cheapest tracked route/tier: OpenRouter

Qwen3.5-Flash

$121

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $776. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Qwen3.5-397B-A17B -> Qwen3.5-Flash
  • Provider overlap exists on Alibaba Cloud PAI-EAS and OpenRouter; start route-level A/B tests there.
  • Qwen3.5-Flash is $2.08/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for Reasoning, JSON / Tool use, and Structured outputs before moving production traffic.
Qwen3.5-Flash -> Qwen3.5-397B-A17B
  • Provider overlap exists on OpenRouter and Alibaba Cloud PAI-EAS; start route-level A/B tests there.
  • Qwen3.5-397B-A17B is $2.08/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Qwen3.5-397B-A17B adds Reasoning, JSON / Tool use, and Structured outputs in local capability data.

Specs

Specification
Released2026-02-162026-02-23
Context window262k1m
Parameters397B
ArchitectureMixture of Experts-
LicenseApache 2.0OSI-approvedApache 2.0OSI-approved
OpennessOpen sourceOpen source
WeightsAvailableUnknown
CodeUnknownUnknown
Commercial useCommercial use: permittedCommercial use: permitted
Knowledge cutoff--

Pricing and availability

Pricing attributeQwen3.5-397B-A17BQwen3.5-Flash
Input price$0.39/1M tokens$0.07/1M tokens
Output price$2.34/1M tokens$0.26/1M tokens
Providers

Capabilities

CapabilityQwen3.5-397B-A17BQwen3.5-Flash
VisionYesYes
MultimodalYesYes
ReasoningYesNo
JSON / Tool useYesNo
Structured outputsYesNo
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkQwen3.5-397B-A17BQwen3.5-Flash
MMLU PRO87.885.3
Google-Proof Q&A89.384.2

Continue comparing

Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.