← All Comparisons
GPT-5.3 Codex vs Gemini 2.5 Pro
A detailed comparison of GPT-5.3 Codex (OpenAI) and Gemini 2.5 Pro (Google) across pricing, performance, and features.
Pricing Comparison
| Metric | GPT-5.3 Codex | Gemini 2.5 Pro | Difference |
|---|---|---|---|
| Input / 1M tokens | $2.00 | $1.25 | -38% |
| Output / 1M tokens | $16.00 | $10.00 | -38% |
| Context window | 200K | 1M | — |
| Max output | 65.536K | 65.536K | — |
Benchmark Comparison
| Benchmark | GPT-5.3 Codex | Gemini 2.5 Pro |
|---|---|---|
| MMLU-Pro | 90% | 87.5% |
| HumanEval | 96.5% | 93.5% |
| GPQA | 78% | 76% |
Capabilities
| Capability | GPT-5.3 Codex | Gemini 2.5 Pro |
|---|---|---|
| audio | ✗ | ✓ |
| 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
Gemini 2.5 Pro Strengths
- ✓Competitive pricing for its capabilities
- ✓1M context window
- ✓Well-tested and stable
Gemini 2.5 Pro Weaknesses
- ✗Being superseded by Gemini 3 Pro
Quick Verdict
Best value: Gemini 2.5 Pro is the more affordable option at $1.25/$10 per 1M tokens.
Higher benchmarks: GPT-5.3 Codex scores higher on average across available benchmarks (88.2% avg).
Larger context: Gemini 2.5 Pro supports 1M tokens.
Choose Gemini 2.5 Pro if cost matters most. Choose GPT-5.3 Codex if you need the best possible quality for complex tasks.