LLM Reference

DeepSeek R1 vs Qwen3.5-35B-A3B

DeepSeek R1 (2025) and Qwen3.5-35B-A3B (2026) are frontier-tier reasoning models from DeepSeek and Alibaba. DeepSeek R1 ships a 128k-token context window, while Qwen3.5-35B-A3B ships a 262k-token context window. On SWE-bench Verified, Qwen3.5-35B-A3B leads by 20 pts. On pricing, DeepSeek R1 costs $0.10/1M input tokens versus $0.14/1M 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 safer overall; choose DeepSeek R1 when coding workflow support matters.

Decision scorecard

Local evidence first
SignalDeepSeek R1Qwen3.5-35B-A3B
Best forreasoning-heavy apps and provider-routed productionreasoning-heavy apps, tool-calling agents, and provider-routed production
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window128k262k
Cheapest output$0.30/1M tokens$1/1M tokens
Provider routes14 tracked2 tracked
Shared benchmarks2 sharedSWE-bench Verified leader

Decision tradeoffs

Choose DeepSeek R1 when...
  • DeepSeek R1 has the lower cheapest tracked output price at $0.30/1M tokens.
  • DeepSeek R1 has broader tracked provider coverage for fallback and route flexibility.
  • DeepSeek R1 uniquely exposes Code execution in local model data.
  • Local decision data tags DeepSeek R1 for Coding, RAG, and Agents.
Choose Qwen3.5-35B-A3B when...
  • Qwen3.5-35B-A3B holds a shared-benchmark lead on SWE-bench Verified, ahead by 20 points.
  • Qwen3.5-35B-A3B has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Qwen3.5-35B-A3B uniquely exposes JSON / Tool use in local model data.
  • 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.

Lower estimate DeepSeek R1

DeepSeek R1

$155

Cheapest tracked route/tier: Bitdeer AI

Qwen3.5-35B-A3B

$361

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $206. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

DeepSeek R1 -> Qwen3.5-35B-A3B
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • Qwen3.5-35B-A3B is $0.70/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Check replacement coverage for Code execution before moving production traffic.
  • Qwen3.5-35B-A3B adds JSON / Tool use in local capability data.
Qwen3.5-35B-A3B -> DeepSeek R1
  • Provider overlap exists on OpenRouter; start route-level A/B tests there.
  • DeepSeek R1 is $0.70/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Check replacement coverage for JSON / Tool use before moving production traffic.
  • DeepSeek R1 adds Code execution in local capability data.

Specs

Specification
Released2025-01-202026-02-24
Context window128k262k
Parameters671B, 37B Active35B
ArchitectureDecoder OnlyMixture of Experts
LicenseMITOSI-approvedApache 2.0OSI-approved
OpennessOpen sourceOpen source
WeightsAvailableAvailable
CodeUnknownUnknown
Commercial useCommercial use: permittedCommercial use: permitted
Knowledge cutoff2023-12-

Pricing and availability

Pricing attributeDeepSeek R1Qwen3.5-35B-A3B
Input price$0.10/1M tokens$0.14/1M tokens
Output price$0.30/1M tokens$1/1M tokens
Providers

Capabilities

CapabilityDeepSeek R1Qwen3.5-35B-A3B
VisionNoNo
MultimodalNoNo
ReasoningYesYes
JSON / Tool useNoYes
Structured outputsYesYes
Code executionYesNo
IDE integrationNoNo
Computer useNoNo
Parallel agentsNoNo

Benchmarks

BenchmarkDeepSeek R1Qwen3.5-35B-A3B
SWE-bench Verified49.269.2
Google-Proof Q&A71.584.5

Continue comparing

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