DeepSeek R1 0528 vs GPT-5.5
DeepSeek R1 0528 (2025) and GPT-5.5 (2026) are frontier-tier reasoning models from DeepSeek and OpenAI. DeepSeek R1 0528 ships a 160K-token context window, while GPT-5.5 ships a 1M-token context window. On Google-Proof Q&A, GPT-5.5 leads by 12.6 pts. On pricing, DeepSeek R1 0528 costs $0.1/1M input tokens versus $5/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
DeepSeek R1 0528 is ~4900% cheaper at $0.1/1M; pay for GPT-5.5 only for coding workflow support.
Specs
| Released | 2025-01-01 | 2026-04-23 |
| Context window | 160K | 1M |
| Parameters | 671B | — |
| Architecture | decoder only | decoder only |
| License | Open Source | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| DeepSeek R1 0528 | GPT-5.5 | |
|---|---|---|
| Input price | $0.1/1M tokens | $5/1M tokens |
| Output price | $0.3/1M tokens | $30/1M tokens |
| Providers |
Capabilities
| DeepSeek R1 0528 | GPT-5.5 | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | DeepSeek R1 0528 | GPT-5.5 |
|---|---|---|
| Google-Proof Q&A | 81.0 | 93.6 |
Deep dive
On shared benchmark coverage, Google-Proof Q&A has DeepSeek R1 0528 at 81 and GPT-5.5 at 93.6, with GPT-5.5 ahead by 12.6 points. The largest visible gap is 12.6 points on Google-Proof Q&A, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: GPT-5.5, multimodal input: GPT-5.5, function calling: GPT-5.5, and tool use: GPT-5.5. Both models share reasoning mode, structured outputs, and code execution, 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 $0.1/1M input and $0.3/1M output tokens, while GPT-5.5 lists $5/1M input and $30/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts DeepSeek R1 0528 lower by about $12.34 per million blended tokens. Availability is 5 providers versus 1, so concentration risk also matters.
Choose DeepSeek R1 0528 when coding workflow support, lower input-token cost, and broader provider choice are central to the workload. Choose GPT-5.5 when coding workflow support 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.
FAQ
Which has a larger context window, DeepSeek R1 0528 or GPT-5.5?
GPT-5.5 supports 1M tokens, while DeepSeek R1 0528 supports 160K 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 GPT-5.5?
DeepSeek R1 0528 is cheaper on tracked token pricing. DeepSeek R1 0528 costs $0.1/1M input and $0.3/1M output tokens. GPT-5.5 costs $5/1M input and $30/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is DeepSeek R1 0528 or GPT-5.5 open source?
DeepSeek R1 0528 is listed under Open Source. GPT-5.5 is listed under Proprietary. 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 GPT-5.5?
GPT-5.5 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 GPT-5.5?
GPT-5.5 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.
Where can I run DeepSeek R1 0528 and GPT-5.5?
DeepSeek R1 0528 is available on Together AI, Fireworks AI, GCP Vertex AI, Novita AI, and OpenRouter. GPT-5.5 is available on OpenAI API. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.