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GPT-5.3 Codex vs DeepSeek V3
A detailed comparison of GPT-5.3 Codex (OpenAI) and DeepSeek V3 (DeepSeek) across pricing, performance, and features.
Pricing Comparison
| Metric | GPT-5.3 Codex | DeepSeek V3 | Difference |
|---|---|---|---|
| Input / 1M tokens | $2.00 | $0.14 | -93% |
| Output / 1M tokens | $16.00 | $0.28 | -98% |
| Context window | 200K | 164K | — |
| Max output | 65.536K | 16.384K | — |
Benchmark Comparison
| Benchmark | GPT-5.3 Codex | DeepSeek V3 |
|---|---|---|
| MMLU-Pro | 90% | 78% |
| HumanEval | 96.5% | 89% |
| GPQA | 78% | — |
Capabilities
| Capability | GPT-5.3 Codex | DeepSeek V3 |
|---|---|---|
| code | ✓ | ✓ |
| reasoning | ✓ | ✓ |
| text | ✓ | ✓ |
| tool-use | ✓ | ✗ |
| vision | ✓ | ✗ |
GPT-5.3 Codex Strengths
- ✓Best coding model from OpenAI
- ✓Large output window (65K tokens)
- ✓Strong reasoning for complex tasks
GPT-5.3 Codex Weaknesses
- ✗API access not yet available
- ✗Premium pricing
DeepSeek V3 Strengths
- ✓Cheapest capable model available
- ✓Strong coding performance
- ✓Open-source
DeepSeek V3 Weaknesses
- ✗No vision support
- ✗Smaller context than competitors
- ✗China-based — availability concerns
Quick Verdict
Best value: DeepSeek V3 is the more affordable option at $0.14/$0.28 per 1M tokens.
Higher benchmarks: GPT-5.3 Codex scores higher on average across available benchmarks (88.2% avg).
Larger context: GPT-5.3 Codex supports 200K tokens.
Choose DeepSeek V3 if cost matters most. Choose GPT-5.3 Codex if you need the best possible quality for complex tasks.