Grok 4.1 Fast vs o3-pro
Compare xAI and OpenAI AI models
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Grok 4.1 Fast
o3-pro
Cost Differences
o3-pro costs more than Grok 4.1 Fast
Feature Comparison
| Feature | Grok 4.1 Fast | o3-pro |
|---|---|---|
| Provider | xAI | OpenAI |
| Input Price | $0.20/1M tokens | $20.00/1M tokens |
| Output Price | $0.50/1M tokens | $80.00/1M tokens |
| Context Window | 2,000,000 tokens | 1,000,000 tokens |
| Max Output | 131,072 tokens | 131,072 tokens |
| Category | efficient | reasoning |
| Capabilities | textreasoningcode | textreasoningcode |
| Release Date | 1/15/2026 | 6/10/2025 |
Grok 4.1 Fast vs o3-pro: Which Should You Choose?
Choosing between Grok 4.1 Fast and o3-pro depends on your priorities: cost efficiency, context length, or raw capability. Grok 4.1 Fast is the more affordable option at $0.20/1M input tokens — 99% cheaper than o3-pro. Meanwhile, Grok 4.1 Fast offers a significantly larger context window at 2,000,000 tokens vs 1,000,000 for o3-pro.
These models come from different providers — xAI and OpenAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with xAI, switching to OpenAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.
These models target different tiers: Grok 4.1 Fast is a efficient model while o3-pro is reasoning. This means they're optimized for different workloads. o3-pro targets more demanding workloads, while Grok 4.1 Fast provides a cost-effective option for everyday tasks.
Output costs matter too. Grok 4.1 Fast charges $0.50/1M output tokens vs $80.00 for o3-pro. For generation-heavy workloads (content creation, code generation, summarization), output pricing often dominates your bill. Grok 4.1 Fast has the edge here at $0.50/1M output tokens.
Best Use Cases
Choose Grok 4.1 Fast when:
- • Budget is a primary concern
- • You need a larger context window (2,000,000 tokens)
- • You're already using xAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
Choose o3-pro when:
- • You're already using OpenAI's API ecosystem
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Grok 4.1 Fast (xAI)
o3-pro (OpenAI)
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