DeepSeek V3.1 vs GPT-5.5-Cyber
DeepSeek V3.1 (2025) and GPT-5.5-Cyber (2026) are frontier reasoning models from DeepSeek and OpenAI. DeepSeek V3.1 ships a 64K-token context window, while GPT-5.5-Cyber ships a not-yet-sourced 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.
GPT-5.5-Cyber is safer overall; choose DeepSeek V3.1 when coding workflow support matters.
Decision scorecard
Local evidence first| Signal | DeepSeek V3.1 | GPT-5.5-Cyber |
|---|---|---|
| Decision fit | Coding, Agents, and Vision | Vision |
| Context window | 64K | — |
| Cheapest output | $1.68/1M tokens | - |
| Provider routes | 6 tracked | 0 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- DeepSeek V3.1 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- DeepSeek V3.1 has broader tracked provider coverage for fallback and procurement flexibility.
- DeepSeek V3.1 uniquely exposes Structured outputs and Code execution in local model data.
- Local decision data tags DeepSeek V3.1 for Coding, Agents, and Vision.
- GPT-5.5-Cyber uniquely exposes Reasoning in local model data.
- Local decision data tags GPT-5.5-Cyber for Vision.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
DeepSeek V3.1
$868
Cheapest tracked route: Fireworks AI
GPT-5.5-Cyber
Unavailable
No complete token price in local provider data
Cost delta unavailable until both models have sourced input and output token prices.
Switch friction
- No overlapping tracked provider route is sourced for DeepSeek V3.1 and GPT-5.5-Cyber; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Structured outputs and Code execution before moving production traffic.
- GPT-5.5-Cyber adds Reasoning in local capability data.
- No overlapping tracked provider route is sourced for GPT-5.5-Cyber and DeepSeek V3.1; plan for SDK, billing, or endpoint changes.
- Check replacement coverage for Reasoning before moving production traffic.
- DeepSeek V3.1 adds Structured outputs and Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-08-21 | 2026-04-30 |
| Context window | 64K | — |
| Parameters | — | — |
| Architecture | mixture of experts | decoder only |
| License | Open Source | Proprietary |
| Knowledge cutoff | - | 2025-12 |
Pricing and availability
| Pricing attribute | DeepSeek V3.1 | GPT-5.5-Cyber |
|---|---|---|
| Input price | $0.56/1M tokens | - |
| Output price | $1.68/1M tokens | - |
| Providers | - |
Capabilities
| Capability | DeepSeek V3.1 | GPT-5.5-Cyber |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | Yes |
| Function calling | No | No |
| Tool use | No | No |
| Structured outputs | Yes | No |
| Code execution | Yes | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on reasoning mode: GPT-5.5-Cyber, structured outputs: DeepSeek V3.1, and code execution: DeepSeek V3.1. Both models share vision and multimodal input, 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 V3.1 has $0.56/1M input tokens and GPT-5.5-Cyber 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 V3.1 when coding workflow support and broader provider choice are central to the workload. Choose GPT-5.5-Cyber when reasoning depth 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. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Is DeepSeek V3.1 or GPT-5.5-Cyber open source?
DeepSeek V3.1 is listed under Open Source. GPT-5.5-Cyber 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 V3.1 or GPT-5.5-Cyber?
Both DeepSeek V3.1 and GPT-5.5-Cyber expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, DeepSeek V3.1 or GPT-5.5-Cyber?
Both DeepSeek V3.1 and GPT-5.5-Cyber expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for reasoning mode, DeepSeek V3.1 or GPT-5.5-Cyber?
GPT-5.5-Cyber 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 V3.1 or GPT-5.5-Cyber?
DeepSeek V3.1 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 V3.1 and GPT-5.5-Cyber?
DeepSeek V3.1 is available on Microsoft Foundry, Fireworks AI, NVIDIA NIM, Together AI, and AWS Bedrock. GPT-5.5-Cyber 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: 2026-05-19. Data sourced from public model cards and provider documentation.