DeepSeek V4 Pro vs GPT-5.5 Pro
DeepSeek V4 Pro (2026) and GPT-5.5 Pro (2026) are frontier-tier reasoning models from DeepSeek and OpenAI. DeepSeek V4 Pro ships a 1m-token context window, while GPT-5.5 Pro ships a 1.05m-token context window. On SWE-bench Verified, GPT-5.5 Pro leads by 2 pts. On pricing, DeepSeek V4 Pro costs $0.43/1M input tokens versus $30/1M 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.
DeepSeek V4 Pro is ~6797% cheaper at $0.43/1M; pay for GPT-5.5 Pro only for coding workflow support.
Decision scorecard
Local evidence first| Signal | DeepSeek V4 Pro | GPT-5.5 Pro |
|---|---|---|
| Best for | reasoning-heavy apps, tool-calling agents, and long-context analysis | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 1.05m |
| Cheapest output | $0.87/1M tokens | $180/1M tokens |
| Provider routes | 5 tracked | 3 tracked |
| Shared benchmarks | 7 shared | SWE-bench Verified leader |
Decision tradeoffs
- DeepSeek V4 Pro holds a shared-benchmark lead on LiveCodeBench, ahead by 2.5 points.
- DeepSeek V4 Pro has the lower cheapest tracked output price at $0.87/1M tokens.
- DeepSeek V4 Pro has broader tracked provider coverage for fallback and route flexibility.
- Local decision data tags DeepSeek V4 Pro for Coding, RAG, and Agents.
- GPT-5.5 Pro holds a shared-benchmark lead on SWE-bench Verified, ahead by 2 points.
- GPT-5.5 Pro has the larger context window for long prompts, retrieval packs, or transcript analysis.
- GPT-5.5 Pro uniquely exposes Vision, Multimodal, and Code execution in local model data.
- Local decision data tags GPT-5.5 Pro 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.
DeepSeek V4 Pro
$566
Cheapest tracked route/tier: DeepSeek Platform
GPT-5.5 Pro
$69,000
Cheapest tracked route/tier: OpenAI API <=272K tokens (standard)
Estimated monthly gap: $68,435. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- GPT-5.5 Pro is $179/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- GPT-5.5 Pro adds Vision, Multimodal, and Code execution in local capability data.
- Provider overlap exists on OpenRouter and Vercel AI Gateway; start route-level A/B tests there.
- DeepSeek V4 Pro is $179/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Code execution before moving production traffic.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-24 | 2026-04-23 |
| Context window | 1m | 1.05m |
| Parameters | 1.6T | — |
| Architecture | Mixture of Experts | Decoder Only |
| License | MITOSI-approved | Proprietary |
| Openness | Open source | Proprietary |
| Weights | Available | Not released |
| Code | Unknown | Unknown |
| Commercial use | Commercial use: permitted | Commercial use: conditional |
| Knowledge cutoff | - | 2025-12 |
Pricing and availability
| Pricing attribute | DeepSeek V4 Pro | GPT-5.5 Pro |
|---|---|---|
| Input price | $0.43/1M tokens | $30/1M tokens |
| Output price | $0.87/1M tokens | $180/1M tokens |
| Providers |
Capabilities
| Capability | DeepSeek V4 Pro | GPT-5.5 Pro |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | Yes |
| Reasoning | Yes | Yes |
| JSON / Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | DeepSeek V4 Pro | GPT-5.5 Pro |
|---|---|---|
| SWE-bench Verified | 80.6 | 82.6 |
| SWE-bench Pro | 55.4 | 58.6 |
| Google-Proof Q&A | 90.1 | 93.6 |
| LiveCodeBench | 93.5 | 91.0 |
| Terminal-Bench 2.0 | 59.1 | 82.7 |
| GeneBench-Pro | 2.4 | 20.5 |
| MCP-Atlas | 69.4 | 75.3 |
Continue comparing
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Last reviewed: 2026-06-29. Data sourced from public model cards and provider documentation.