The latest and strongest model family from OpenAI, o1 is designed to spend more time thinking before responding. The o1 model series is trained with large-scale reinforcement learning to reason using chain of thought. The o1 models are op…
Model details →OpenAI: o1 vs xAI: Grok 4 Fast
xAI: Grok 4 Fast wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
Grok 4 Fast is xAI's latest multimodal model with SOTA cost-efficiency and a 2M token context window. It comes in two flavors: non-reasoning and reasoning. Read more about the model on xAI's [news post](http://x.ai/news/grok-4-fast). Reaso…
Model details →Side-by-side comparison
| Capability | OpenAI: o1 | xAI: Grok 4 Fast | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 200K | 2M | 🏆 xAI: Grok 4 Fast |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $15.00 | $0.20 | 🏆 xAI: Grok 4 Fast |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $60.00 | $0.50 | 🏆 xAI: Grok 4 Fast |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | Yes | Yes | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is OpenAI: o1 better than xAI: Grok 4 Fast?
xAI: Grok 4 Fast wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between OpenAI: o1 and xAI: Grok 4 Fast?
Input: $15.00 vs $0.20 per 1M tokens. Output: $60.00 vs $0.50 per 1M tokens.
What context windows do OpenAI: o1 and xAI: Grok 4 Fast support?
OpenAI: o1 supports up to 200K tokens. xAI: Grok 4 Fast supports up to 2M tokens.
Do both OpenAI: o1 and xAI: Grok 4 Fast support tool calling?
OpenAI: o1: yes. xAI: Grok 4 Fast: yes.