DeepSeek R1 vs GPT-5.5
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for DeepSeek R1 and GPT-5.5.
DeepSeek R1
A premier reasoning model employing large-scale reinforcement learning. Displays specialized math, coding, and logical validation capabilities comparable to OpenAI's o1.
GPT-5.5
GPT-5.5 is OpenAI’s frontier model designed for complex professional workloads, building on GPT-5.4 with stronger reasoning, higher reliability, and improved token efficiency on hard tasks. It features a 1M+ token...
Technical Specifications
| Specification | DeepSeek R1 | GPT-5.5 |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| Context Window | 163,840 tokens | 1,050,000 tokens |
| Agent Suitability | 78/100 | 95/100 |
| Time to First Token (TTFT) | 1800 ms | 380 ms |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2025-01-20 | 2026-04-24 |
API Pricing Comparison
Input Price per Million Tokens
DeepSeek R1
$0.70
GPT-5.5
$5.00
Output Price per Million Tokens
DeepSeek R1
$2.50
GPT-5.5
$30.00
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Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
DeepSeek R1 Quirks & Gotchas
- ▸Reasoning model — not designed for high-frequency tool calling
- ▸Pair with a smaller model (V4 Flash) for routing and use R1 for complex reasoning only
GPT-5.5 Quirks & Gotchas
- ▸Best for JSON schema adherence — strict mode available via response_format parameter
- ▸Requires explicit tool_choice for deterministic function calling