Key Takeaways
Gemini 3 Flash Preview wins:
- Cheaper input tokens
- Cheaper output tokens
- Larger context window
- Faster response time
- Better at math
GPT-5.3 Codex wins:
- Higher intelligence benchmark
- Better at coding
Price Advantage
Gemini 3 Flash Preview
Benchmark Advantage
GPT-5.3 Codex
Context Window
Gemini 3 Flash Preview
Speed
Gemini 3 Flash Preview
Pricing Comparison
Price Comparison
| Metric | Gemini 3 Flash Preview | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $0.50 | $1.75 | Gemini 3 Flash Preview |
| Output (per 1M tokens) | $3.00 | $14.00 | Gemini 3 Flash Preview |
| Cache Read (per 1M) | $0.05 | $0.17 | Gemini 3 Flash Preview |
| Cache Write (per 1M) | $0.08 | N/A | Gemini 3 Flash Preview |
Using a 3:1 input/output ratio, Gemini 3 Flash Preview is 77% cheaper overall.
Gemini 3 Flash Preview Providers
No provider data available
GPT-5.3 Codex Providers
No provider data available
Benchmark Comparison
6
Benchmarks Compared
0
Gemini 3 Flash Preview Wins
3
GPT-5.3 Codex Wins
Benchmark Scores
| Benchmark | Gemini 3 Flash Preview | GPT-5.3 Codex | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 35.0 | 54.0 | |
Coding Index Code generation & understanding | 37.8 | 53.1 | |
Math Index Mathematical reasoning | 55.7 | - | - |
MMLU Pro Academic knowledge | 88.2 | - | - |
GPQA Graduate-level science | 81.2 | 91.5 | |
LiveCodeBench Competitive programming | 79.7 | - | - |
GPT-5.3 Codex significantly outperforms in coding benchmarks.
Cost vs Quality
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Gemini 3 Flash Preview
Other models
Context & Performance
Context Window
Gemini 3 Flash Preview
1,048,576
tokens
GPT-5.3 Codex
400,000
tokens
Gemini 3 Flash Preview has a 62% larger context window.
Speed Performance
| Metric | Gemini 3 Flash Preview | GPT-5.3 Codex | Winner |
|---|---|---|---|
| Tokens/second | 175.7 tok/s | 68.4 tok/s | |
| Time to First Token | 0.86s | 87.36s |
Gemini 3 Flash Preview responds 157% faster on average.
Capabilities
Feature Comparison
| Feature | Gemini 3 Flash Preview | GPT-5.3 Codex |
|---|---|---|
| Vision (Image Input) | ||
| Tool/Function Calls | ||
| Reasoning Mode | ||
| Audio Input | ||
| Audio Output | ||
| PDF Input | ||
| Prompt Caching | ||
| Web Search |
License & Release
| Property | Gemini 3 Flash Preview | GPT-5.3 Codex |
|---|---|---|
| License | Proprietary | Proprietary |
| Author | OpenAI | |
| Released | Dec 2025 | Feb 2026 |
Gemini 3 Flash Preview Modalities
Input
textimagefileaudiovideo
Output
text
GPT-5.3 Codex Modalities
Input
textimage
Output
text