Key Takeaways
DeepSeek V3.1 Terminus wins:
- Cheaper input tokens
- Cheaper output tokens
- Better at math
GPT-5.3 Codex wins:
- Larger context window
- Faster response time
- Higher intelligence benchmark
- Better at coding
- Supports vision
Price Advantage
DeepSeek V3.1 Terminus
Benchmark Advantage
GPT-5.3 Codex
Context Window
GPT-5.3 Codex
Speed
GPT-5.3 Codex
Pricing Comparison
Price Comparison
| Metric | DeepSeek V3.1 Terminus | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $0.21 | $1.75 | DeepSeek V3.1 Terminus |
| Output (per 1M tokens) | $0.79 | $14.00 | DeepSeek V3.1 Terminus |
| Cache Read (per 1M) | $0.12 | $0.17 | DeepSeek V3.1 Terminus |
Using a 3:1 input/output ratio, DeepSeek V3.1 Terminus is 93% cheaper overall.
DeepSeek V3.1 Terminus Providers
No provider data available
GPT-5.3 Codex Providers
No provider data available
Benchmark Comparison
6
Benchmarks Compared
0
DeepSeek V3.1 Terminus Wins
3
GPT-5.3 Codex Wins
Benchmark Scores
| Benchmark | DeepSeek V3.1 Terminus | GPT-5.3 Codex | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 28.5 | 54.0 | |
Coding Index Code generation & understanding | 31.9 | 53.1 | |
Math Index Mathematical reasoning | 53.7 | - | - |
MMLU Pro Academic knowledge | 83.6 | - | - |
GPQA Graduate-level science | 75.1 | 91.5 | |
LiveCodeBench Competitive programming | 52.9 | - | - |
GPT-5.3 Codex significantly outperforms in coding benchmarks.
Cost vs Quality
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DeepSeek V3.1 Terminus
Other models
Context & Performance
Context Window
DeepSeek V3.1 Terminus
163,840
tokens
GPT-5.3 Codex
400,000
tokens
GPT-5.3 Codex has a 59% larger context window.
Speed Performance
| Metric | DeepSeek V3.1 Terminus | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Tokens/second | 0.0 tok/s | 68.4 tok/s | |
| Time to First Token | 0.00s | 87.36s |
GPT-5.3 Codex responds Infinity% faster on average.
Capabilities
Feature Comparison
| Feature | DeepSeek V3.1 Terminus | GPT-5.3 Codex |
|---|---|---|
| Vision (Image Input) | ||
| Tool/Function Calls | ||
| Reasoning Mode | ||
| Audio Input | ||
| Audio Output | ||
| PDF Input | ||
| Prompt Caching | ||
| Web Search |
License & Release
| Property | DeepSeek V3.1 Terminus | GPT-5.3 Codex |
|---|---|---|
| License | Open Source | Proprietary |
| Author | Deepseek | OpenAI |
| Released | Sep 2025 | Feb 2026 |
DeepSeek V3.1 Terminus Modalities
Input
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Output
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GPT-5.3 Codex Modalities
Input
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Output
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