LLM Reference

DeepSeek R1 0528 vs Qwen3.5-4B

DeepSeek R1 0528 (2025) and Qwen3.5-4B (2026) are frontier reasoning models from DeepSeek and Alibaba. DeepSeek R1 0528 ships a 130K-token context window, while Qwen3.5-4B ships a 262K-token context window. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing. The goal is to make the tradeoff clear before deeper testing.

Qwen3.5-4B is safer overall; choose DeepSeek R1 0528 when coding workflow support matters.

Decision scorecard

Local evidence first
SignalDeepSeek R1 0528Qwen3.5-4B
Best forreasoning-heavy apps and provider-routed productionmultimodal apps
Decision fitCoding, RAG, and AgentsLong context and Vision
Context window130K262K
Cheapest output$2.15/1M tokens-
Provider routes6 tracked0 tracked
Shared benchmarks0 rows0 rows

Decision tradeoffs

Choose DeepSeek R1 0528 when...
  • DeepSeek R1 0528 has broader tracked provider coverage for fallback and procurement flexibility.
  • DeepSeek R1 0528 uniquely exposes Reasoning, Structured outputs, and Code execution in local model data.
  • Local decision data tags DeepSeek R1 0528 for Coding, RAG, and Agents.
Choose Qwen3.5-4B when...
  • Qwen3.5-4B has the larger context window for long prompts, retrieval packs, or transcript analysis.
  • Qwen3.5-4B uniquely exposes Vision and Multimodal in local model data.
  • Local decision data tags Qwen3.5-4B for Long context and Vision.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

DeepSeek R1 0528

$938

Cheapest tracked route/tier: OpenRouter

Qwen3.5-4B

Unavailable

No complete token price in local provider data

Cost delta unavailable until both models have sourced input and output token prices.

Switch friction

DeepSeek R1 0528 -> Qwen3.5-4B
  • No overlapping tracked provider route is sourced for DeepSeek R1 0528 and Qwen3.5-4B; plan for SDK, billing, or endpoint changes.
  • Check replacement coverage for Reasoning, Structured outputs, and Code execution before moving production traffic.
  • Qwen3.5-4B adds Vision and Multimodal in local capability data.
Qwen3.5-4B -> DeepSeek R1 0528
  • No overlapping tracked provider route is sourced for Qwen3.5-4B and DeepSeek R1 0528; plan for SDK, billing, or endpoint changes.
  • Check replacement coverage for Vision and Multimodal before moving production traffic.
  • DeepSeek R1 0528 adds Reasoning, Structured outputs, and Code execution in local capability data.

Specs

Specification
Released2025-05-282026-03-02
Context window130K262K
Parameters685B total, 37B active (MoE)4B
Architecturedecoder only-
LicenseOpen SourceApache 2.0
Knowledge cutoff--

Pricing and availability

Pricing attributeDeepSeek R1 0528Qwen3.5-4B
Input price$0.50/1M tokens-
Output price$2.15/1M tokens-
Providers-

Capabilities

CapabilityDeepSeek R1 0528Qwen3.5-4B
VisionNoYes
MultimodalNoYes
ReasoningYesNo
Function callingNoNo
Tool useNoNo
Structured outputsYesNo
Code executionYesNo
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: Qwen3.5-4B, multimodal input: Qwen3.5-4B, reasoning mode: DeepSeek R1 0528, structured outputs: DeepSeek R1 0528, and code execution: DeepSeek R1 0528. 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.

Pricing coverage is uneven: DeepSeek R1 0528 has $0.50/1M input tokens and Qwen3.5-4B has no token price sourced yet. Provider availability is 6 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.

Choose DeepSeek R1 0528 when coding workflow support and broader provider choice are central to the workload. Choose Qwen3.5-4B when long-context analysis and larger context windows 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, DeepSeek R1 0528 or Qwen3.5-4B?

Qwen3.5-4B supports 262K tokens, while DeepSeek R1 0528 supports 130K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Is DeepSeek R1 0528 or Qwen3.5-4B open source?

DeepSeek R1 0528 is listed under Open Source. Qwen3.5-4B 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, DeepSeek R1 0528 or Qwen3.5-4B?

Qwen3.5-4B 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, DeepSeek R1 0528 or Qwen3.5-4B?

Qwen3.5-4B 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.

Which is better for reasoning mode, DeepSeek R1 0528 or Qwen3.5-4B?

DeepSeek R1 0528 has the clearer documented reasoning mode signal in this comparison. If reasoning mode is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.

Where can I run DeepSeek R1 0528 and Qwen3.5-4B?

DeepSeek R1 0528 is available on Together AI, Fireworks AI, GCP Vertex AI, Novita AI, and OpenRouter. Qwen3.5-4B is available on the tracked providers still being sourced. 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.