Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Grok 4
o3-pro
Cost Differences
o3-pro costs more than Grok 4
Feature Comparison
| Feature | Grok 4 | o3-pro |
|---|---|---|
| Provider | xAI | OpenAI |
| Input Price | $3.00/1M tokens | $20.00/1M tokens |
| Output Price | $15.00/1M tokens | $80.00/1M tokens |
| Context Window | 256,000 tokens | 1,000,000 tokens |
| Max Output | 131,072 tokens | 131,072 tokens |
| Category | reasoning | reasoning |
| Capabilities | textvisionreasoningcode | textreasoningcode |
| Release Date | 7/9/2025 | 6/10/2025 |
Grok 4 vs o3-pro: Which Should You Choose?
Choosing between Grok 4 and o3-pro depends on your priorities: cost efficiency, context length, or raw capability. Grok 4 is the more affordable option at $3.00/1M input tokens — 85% cheaper than o3-pro. Meanwhile, o3-pro offers a significantly larger context window at 1,000,000 tokens vs 256,000 for Grok 4.
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.
Both models are in the reasoning category, making this a direct head-to-head comparison. At scale — say 10,000 requests per day — the cost difference adds up: Grok 4 would save you roughly $14,850.00/month compared to o3-pro. For startups and indie developers, that difference can be significant.
Output costs matter too. Grok 4 charges $15.00/1M 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 has the edge here at $15.00/1M output tokens.
Multimodal capabilities: Grok 4 supports vision (image inputs) while o3-pro is text-only. If your application needs image understanding, this narrows your choice.
Best Use Cases
Choose Grok 4 when:
- • Budget is a primary concern
- • You need more capabilities (vision)
- • You're already using xAI's API ecosystem
Choose o3-pro when:
- • You need a larger context window (1,000,000 tokens)
- • 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 (xAI)
o3-pro (OpenAI)
Start using Grok 4 today
Sign Up for xAI →Start using o3-pro today
Sign Up for OpenAI →