Gemini 1.5 Flash vs GPT-5.3-Codex
Google vs OpenAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.3-Codex has the higher intelligence index (91.5 vs 61.9)
- •Gemini 1.5 Flash is cheaper ($0.15 vs $1.75 per 1M input)
- •Gemini 1.5 Flash is faster
- •Gemini 1.5 Flash has a larger context window (1M)
| Gemini 1.5 Flash | GPT-5.3-Codex | |
|---|---|---|
| Intelligence index | 61.9 | 91.5 |
| Developer | OpenAI | |
| Type | Multimodal | Multimodal |
| Access | API only | API only |
| Context window | 1,048,576 tokens | 400,000 tokens |
| Input price | $0.15 / 1M | $1.75 / 1M |
| Output price | $0.60 / 1M | $14.00 / 1M |
| Speed | 150 tok/s | 73 tok/s |
| Released | May 1, 2024 | February 24, 2026 |
| Parameters | — | — |
| Input modalities | — | Text, Image |
| Output modalities | — | Text |
Shared benchmarks
Gemini 1.5 Flash
GPT-5.3-Codex
GPQA Diamond
51
91.5
Humanity’s Last Exam
4.2
39.9