Gemini 3.5 Flash vs GPT-5.3-Codex
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.
Gemini 3.5 Flash vs GPT-5.3-Codex: side by side
| Spec | Gemini 3.5 Flash | GPT-5.3-Codex | Winner |
|---|---|---|---|
| Intelligence | 45.4 | 44.3 | Gemini 3.5 Flash |
| Output speed | 157 t/s | 79 t/s | Gemini 3.5 Flash |
| Output price | $9.00/1M | $14.00/1M | Gemini 3.5 Flash |
| Context | 1049K | 400K | Gemini 3.5 Flash |
| Params | — | — | Tie |
| Provider | OpenAI | Tie |
Gemini 3.5 Flash
Pros
- +High speed and efficiency
- +Strong multimodal integration
- +Large context window support
Cons
- –Trades depth for speed on complex tasks
- –Variable performance on specialized domains
- –Context utilization depends on task
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
Frequently asked questions
It depends on your needs. Gemini 3.5 Flash and GPT-5.3-Codex are both multimodal models; the comparison table above shows where each one leads on the metrics that matter. See the verdict for a recommendation.