Key Takeaways
Gemini 2.5 Pro wins:
- Larger context window
- Faster response time
- Has reasoning mode
GPT-5.1-Codex wins:
- Higher intelligence benchmark
- Better at coding
- Better at math
Price Advantage
Gemini 2.5 Pro
Benchmark Advantage
GPT-5.1-Codex
Context Window
Gemini 2.5 Pro
Speed
Gemini 2.5 Pro
Pricing Comparison
Price Comparison
| Metric | Gemini 2.5 Pro | GPT-5.1-Codex | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $1.25 | $1.25 | Tie |
| Output (per 1M tokens) | $10.00 | $10.00 | Tie |
| Cache Read (per 1M) | $0.13 | $0.13 | Tie |
| Cache Write (per 1M) | $0.38 | N/A | Gemini 2.5 Pro |
Both models have similar overall pricing.
Gemini 2.5 Pro Providers
Google AI Studio $1.00 (Cheapest)
Google $1.25
Vercel $2.50
GPT-5.1-Codex Providers
OpenAI $1.25 (Cheapest)
Azure $1.25 (Cheapest)
Benchmark Comparison
7
Benchmarks Compared
0
Gemini 2.5 Pro Wins
5
GPT-5.1-Codex Wins
Benchmark Scores
| Benchmark | Gemini 2.5 Pro | GPT-5.1-Codex | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 34.6 | 43.1 | |
Coding Index Code generation & understanding | 31.9 | 36.6 | |
Math Index Mathematical reasoning | 87.7 | 95.7 | |
MMLU Pro Academic knowledge | 86.2 | 86.0 | - |
GPQA Graduate-level science | 84.4 | 86.0 | |
LiveCodeBench Competitive programming | 80.1 | 84.9 | |
AIME Competition math | 88.7 | - | - |
GPT-5.1-Codex shows stronger mathematical reasoning abilities.
Cost vs Quality
X-axis:
Y-axis:
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Gemini 2.5 Pro
Other models
Context & Performance
Context Window
Gemini 2.5 Pro
1,048,576
tokens
Max output: 65,536 tokens
GPT-5.1-Codex
400,000
tokens
Max output: 128,000 tokens
Gemini 2.5 Pro has a 62% larger context window.
Speed Performance
| Metric | Gemini 2.5 Pro | GPT-5.1-Codex | Winner |
|---|---|---|---|
| Tokens/second | 126.6 tok/s | 103.6 tok/s | |
| Time to First Token | 25.27s | 6.57s |
Gemini 2.5 Pro responds 22% faster on average.
Capabilities
Feature Comparison
| Feature | Gemini 2.5 Pro | GPT-5.1-Codex |
|---|---|---|
| Vision (Image Input) | ||
| Tool/Function Calls | ||
| Reasoning Mode | ||
| Audio Input | ||
| Audio Output | ||
| PDF Input | ||
| Prompt Caching | ||
| Web Search |
License & Release
| Property | Gemini 2.5 Pro | GPT-5.1-Codex |
|---|---|---|
| License | Proprietary | Proprietary |
| Author | OpenAI | |
| Released | Jun 2025 | Nov 2025 |
Gemini 2.5 Pro Modalities
Input
textimagefileaudiovideo
Output
text
GPT-5.1-Codex Modalities
Input
textimage
Output
text