← All Comparisons
Gemini 3.1 Pro vs GPT-5.3 Codex
A detailed comparison of Gemini 3.1 Pro (Google) and GPT-5.3 Codex (OpenAI) across pricing, performance, and features.
Pricing Comparison
| Metric | Gemini 3.1 Pro | GPT-5.3 Codex | Difference |
|---|---|---|---|
| Input / 1M tokens | $2.00 | $2.00 | — |
| Output / 1M tokens | $12.00 | $16.00 | +33% |
| Context window | 1M | 200K | — |
| Max output | 64K | 65.536K | — |
Benchmark Comparison
| Benchmark | Gemini 3.1 Pro | GPT-5.3 Codex |
|---|---|---|
| MMLU-Pro | 91% | 90% |
| HumanEval | 95% | 96.5% |
| GPQA | 94.3% | 78% |
Capabilities
| Capability | Gemini 3.1 Pro | GPT-5.3 Codex |
|---|---|---|
| audio | ✓ | ✗ |
| code | ✓ | ✓ |
| reasoning | ✓ | ✓ |
| text | ✓ | ✓ |
| tool-use | ✓ | ✓ |
| vision | ✓ | ✓ |
Gemini 3.1 Pro Strengths
- ✓#1 on 12 of 18 tracked benchmarks
- ✓94.3% GPQA Diamond — highest of any model
- ✓Same price as Gemini 3 Pro (free upgrade)
- ✓1M context with configurable thinking levels
Gemini 3.1 Pro Weaknesses
- ✗Still in preview
- ✗Context-tiered pricing ($4/$18 above 200K)
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
Quick Verdict
Best value: Gemini 3.1 Pro is the more affordable option at $2/$12 per 1M tokens.
Higher benchmarks: Gemini 3.1 Pro scores higher on average across available benchmarks (93.4% avg).
Larger context: Gemini 3.1 Pro supports 1M tokens.
Choose Gemini 3.1 Pro if cost matters most. Choose GPT-5.3 Codex if you need the best possible quality for complex tasks.