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GPT-4o vs GPT-5.3 Codex
A detailed comparison of GPT-4o (OpenAI) and GPT-5.3 Codex (OpenAI) across pricing, performance, and features.
Pricing Comparison
| Metric | GPT-4o | GPT-5.3 Codex | Difference |
|---|---|---|---|
| Input / 1M tokens | $2.50 | $2.00 | -20% |
| Output / 1M tokens | $10.00 | $16.00 | +60% |
| Context window | 128K | 200K | — |
| Max output | 16.384K | 65.536K | — |
Benchmark Comparison
| Benchmark | GPT-4o | GPT-5.3 Codex |
|---|---|---|
| MMLU-Pro | 80.5% | 90% |
| HumanEval | 91% | 96.5% |
| GPQA | 64.2% | 78% |
Capabilities
| Capability | GPT-4o | GPT-5.3 Codex |
|---|---|---|
| audio | ✓ | ✗ |
| code | ✓ | ✓ |
| reasoning | ✗ | ✓ |
| text | ✓ | ✓ |
| tool-use | ✓ | ✓ |
| vision | ✓ | ✓ |
GPT-4o Strengths
- ✓Well-established and reliable
- ✓Large ecosystem of tools and integrations
GPT-4o Weaknesses
- ✗Being superseded by GPT-5 series
- ✗Higher price than newer, better alternatives
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: GPT-4o is the more affordable option at $2.5/$10 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 GPT-4o if cost matters most. Choose GPT-5.3 Codex if you need the best possible quality for complex tasks.