DeepSeek R1 0528 vs Phi 3.5 MoE Instruct
DeepSeek R1 0528 (2025) and Phi 3.5 MoE Instruct (2024) are frontier reasoning models from DeepSeek and Microsoft Research. DeepSeek R1 0528 ships a 130k-token context window, while Phi 3.5 MoE Instruct ships a 128k-token context window. On pricing, both list $0.50/1M input tokens on the cheapest tracked route. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
DeepSeek R1 0528 is safer overall; choose Phi 3.5 MoE Instruct when provider fit matters.
Decision scorecard
Local evidence first| Signal | DeepSeek R1 0528 | Phi 3.5 MoE Instruct |
|---|---|---|
| Best for | reasoning-heavy apps and provider-routed production | general production evaluation |
| Decision fit | Coding, RAG, and Agents | Long context |
| Context window | 130k | 128k |
| Cheapest output | $2.15/1M tokens | $0.50/1M tokens |
| Provider routes | 6 tracked | 1 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- DeepSeek R1 0528 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- 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.
- Phi 3.5 MoE Instruct has the lower cheapest tracked output price at $0.50/1M tokens.
- Local decision data tags Phi 3.5 MoE Instruct for Long context.
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
Phi 3.5 MoE Instruct
$525
Cheapest tracked route/tier: Fireworks AI
Estimated monthly gap: $413. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on Fireworks AI; start route-level A/B tests there.
- Phi 3.5 MoE Instruct is $1.65/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Reasoning, Structured outputs, and Code execution before moving production traffic.
- Provider overlap exists on Fireworks AI; start route-level A/B tests there.
- DeepSeek R1 0528 is $1.65/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- DeepSeek R1 0528 adds Reasoning, Structured outputs, and Code execution in local capability data.
Specs
Pricing and availability
| Pricing attribute | DeepSeek R1 0528 | Phi 3.5 MoE Instruct |
|---|---|---|
| Input price | $0.50/1M tokens | $0.50/1M tokens |
| Output price | $2.15/1M tokens | $0.50/1M tokens |
| Providers |
Capabilities
| Capability | DeepSeek R1 0528 | Phi 3.5 MoE Instruct |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | Yes | No |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on 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.
For cost, DeepSeek R1 0528 lists $0.50/1M input and $2.15/1M output tokens on the cheapest tracked provider, while Phi 3.5 MoE Instruct lists $0.50/1M input and $0.50/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Phi 3.5 MoE Instruct lower by about $0.49 per million blended tokens. Availability is 6 providers versus 1, so concentration risk also matters.
Choose DeepSeek R1 0528 when coding workflow support, larger context windows, and broader provider choice are central to the workload. Choose Phi 3.5 MoE Instruct when provider fit 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.
FAQ
Which has a larger context window, DeepSeek R1 0528 or Phi 3.5 MoE Instruct?
DeepSeek R1 0528 supports 130k tokens, while Phi 3.5 MoE Instruct supports 128k tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, DeepSeek R1 0528 or Phi 3.5 MoE Instruct?
Phi 3.5 MoE Instruct is cheaper on tracked token pricing. DeepSeek R1 0528 costs $0.50/1M input and $2.15/1M output tokens. Phi 3.5 MoE Instruct costs $0.50/1M input and $0.50/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is DeepSeek R1 0528 or Phi 3.5 MoE Instruct open source?
DeepSeek R1 0528 is listed under MIT. Phi 3.5 MoE Instruct is listed under MIT. 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 reasoning mode, DeepSeek R1 0528 or Phi 3.5 MoE Instruct?
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.
Which is better for structured outputs, DeepSeek R1 0528 or Phi 3.5 MoE Instruct?
DeepSeek R1 0528 has the clearer documented structured outputs signal in this comparison. If structured outputs 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 Phi 3.5 MoE Instruct?
DeepSeek R1 0528 is available on Together AI, Fireworks AI, GCP Vertex AI, Novita AI, and OpenRouter. Phi 3.5 MoE Instruct is available on Fireworks AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-05-22. Data sourced from public model cards and provider documentation.