LLM Reference

Qwen2.5-72B-Instruct vs Qwen3.5-397B-A17B

Qwen2.5-72B-Instruct (2024) and Qwen3.5-397B-A17B (2026) are frontier reasoning models from Alibaba. Qwen2.5-72B-Instruct ships a 128k-token context window, while Qwen3.5-397B-A17B ships a 262k-token context window. On Google-Proof Q&A, Qwen3.5-397B-A17B leads by 50.9 pts. On pricing, Qwen2.5-72B-Instruct costs $0.18/1M 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.

Qwen2.5-72B-Instruct is ~117% cheaper at $0.18/1M; pay for Qwen3.5-397B-A17B only for reasoning depth.

Decision scorecard

Local evidence first
SignalQwen2.5-72B-InstructQwen3.5-397B-A17B
Best forprovider-routed productionreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and Long contextCoding, RAG, and Agents
Context window128k262k
Cheapest output$0.54/1M tokens$2.34/1M tokens
Provider routes7 tracked4 tracked
Shared benchmarks1 sharedGoogle-Proof Q&A leader

Decision tradeoffs

Choose Qwen2.5-72B-Instruct when...
  • Qwen2.5-72B-Instruct has the lower cheapest tracked output price at $0.54/1M tokens.
  • Qwen2.5-72B-Instruct has broader tracked provider coverage for fallback and route flexibility.
  • Local decision data tags Qwen2.5-72B-Instruct for Coding, RAG, and Long context.
Choose Qwen3.5-397B-A17B when...
  • Qwen3.5-397B-A17B holds a shared-benchmark lead on Google-Proof Q&A, ahead by 50.9 points.
  • Qwen3.5-397B-A17B has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Qwen3.5-397B-A17B uniquely exposes Vision, Multimodal, and Reasoning in local model data.
  • Local decision data tags Qwen3.5-397B-A17B 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 Qwen2.5-72B-Instruct

Qwen2.5-72B-Instruct

$279

Cheapest tracked route/tier: Chutes AI

Qwen3.5-397B-A17B

$897

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $618. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Qwen2.5-72B-Instruct -> Qwen3.5-397B-A17B
  • Provider overlap exists on OpenRouter and Novita AI; start route-level A/B tests there.
  • Qwen3.5-397B-A17B is $1.80/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Qwen3.5-397B-A17B adds Vision, Multimodal, and Reasoning in local capability data.
Qwen3.5-397B-A17B -> Qwen2.5-72B-Instruct
  • Provider overlap exists on OpenRouter and Novita AI; start route-level A/B tests there.
  • Qwen2.5-72B-Instruct is $1.80/1M 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
Released2024-06-072026-02-16
Context window128k262k
Parameters72.7B397B
ArchitectureDecoder OnlyMixture of Experts
LicenseApache 2.0OSI-approvedApache 2.0OSI-approved
OpennessOpen sourceOpen source
WeightsAvailableAvailable
CodeUnknownUnknown
Commercial useCommercial use: permittedCommercial use: permitted
Knowledge cutoff--

Pricing and availability

Pricing attributeQwen2.5-72B-InstructQwen3.5-397B-A17B
Input price$0.18/1M tokens$0.39/1M tokens
Output price$0.54/1M tokens$2.34/1M tokens
Providers

Capabilities

CapabilityQwen2.5-72B-InstructQwen3.5-397B-A17B
VisionNoYes
MultimodalNoYes
ReasoningNoYes
JSON / Tool useNoYes
Structured outputsYesYes
Code executionNoNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkQwen2.5-72B-InstructQwen3.5-397B-A17B
Google-Proof Q&A38.489.3

Continue comparing

Last reviewed: 2026-06-30. Data sourced from public model cards and provider documentation.