GPT-5.3-Codex vs Grok 4.3
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
GPT-5.3-Codex vs Grok 4.3: side by side
| Spec | GPT-5.3-Codex | Grok 4.3 | Winner |
|---|---|---|---|
| Intelligence | 53.6 | 43.9 | GPT-5.3-Codex |
| Output speed | 101 t/s | 135 t/s | Grok 4.3 |
| Output price | $14.00/1M | $2.50/1M | Grok 4.3 |
| Context | 400K | 1000K | Grok 4.3 |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | xAI | Tie |
GPT-5.3-Codex
Pros
- +Specialized for programming workflows
- +Extensive context handling
- +Support for diverse input types
Cons
- –Narrower focus than general-purpose models
- –Performance tied to input quality
Grok 4.3
Pros
- +Strong performance on complex multi-step reasoning
- +Large context window for document-level tasks
- +Helpful and direct response style
- +Integrated real-time tool access
Cons
- –Vision capabilities less mature than specialized models
- –Occasional over-refusal on edge-case queries
- –High computational cost for maximum context usage
Frequently asked questions
It depends on your needs. GPT-5.3-Codex and Grok 4.3 are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.