Gemini 3.5 Flash vs Grok 4 Fast
Google vs xAI — benchmarks, pricing, and capabilities side by side.
- •Gemini 3.5 Flash has the higher intelligence index (92.2 vs 78.7)
- •Grok 4 Fast is cheaper ($0.20 vs $1.50 per 1M input)
- •Gemini 3.5 Flash is faster
- •Grok 4 Fast has a larger context window (2M)
| Gemini 3.5 Flash | Grok 4 Fast | |
|---|---|---|
| Intelligence index | 92.2 | 78.7 |
| Developer | xAI | |
| Type | Multimodal | LLM |
| Access | API only | API only |
| Context window | 1,048,576 tokens | 2,000,000 tokens |
| Input price | $1.50 / 1M | $0.20 / 1M |
| Output price | $9.00 / 1M | $0.50 / 1M |
| Speed | 221 tok/s | 90 tok/s |
| Released | May 19, 2026 | September 19, 2025 |
| Parameters | — | — |
| Input modalities | Text, Image, Audio, Video | Text, Image |
| Output modalities | Text | Text |
Shared benchmarks
Gemini 3.5 Flash
Grok 4 Fast
GPQA Diamond
92.2
85.7
Humanity’s Last Exam
41
20