Grok 3 Mini vs Grok 4.1 Fast
Grok 3 Mini vs Grok 4.1 Fast: Grok 4.1 Fast is cheaper for input-heavy usage ($0.20/M vs $0.30/M input tokens), while Grok 4.1 Fast is better for long-context tasks (2,000,000 tokens).
Direct answer: choose Grok 4.1 Fast for lower token spend and choose Grok 4.1 Fast when your workload needs longer context.
Compare input and output token pricing, context windows, and monthly cost estimates on one page so you can pick the cheaper model fast.
Cost Comparison (1000 input + 500 output tokens, 100 requests/day)
Grok 3 Mini
Grok 4.1 Fast
Cost Differences
Grok 4.1 Fast costs less than Grok 3 Mini
Quick Recommendation
Winner for direct API pricing: Grok 4.1 Fast. At the default workload, Grok 4.1 Fast saves about $0.30/month ($3.65/year) versus Grok 3 Mini.
Feature Comparison
| Feature | Grok 3 Mini | Grok 4.1 Fast |
|---|---|---|
| Provider | xAI | xAI |
| Input Price | $0.30/1M tokens | $0.20/1M tokens |
| Output Price | $0.50/1M tokens | $0.50/1M tokens |
| Context Window | 128,000 tokens | 2,000,000 tokens |
| Max Output | 131,072 tokens | 131,072 tokens |
| Category | efficient | efficient |
| Capabilities | textreasoningcode | textreasoningcode |
| Release Date | 2/17/2025 | 1/15/2026 |
Grok 3 Mini vs Grok 4.1 Fast: Which Should You Choose?
Choosing between Grok 3 Mini and Grok 4.1 Fast 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 — 33% cheaper than Grok 3 Mini. Meanwhile, Grok 4.1 Fast offers a significantly larger context window at 2,000,000 tokens vs 128,000 for Grok 3 Mini.
Both models are in the efficient category, making this a direct head-to-head comparison. At scale — say 10,000 requests per day — the cost difference adds up: Grok 4.1 Fast would save you roughly $30.00/month compared to Grok 3 Mini. For startups and indie developers, that difference can be significant.
Output costs matter too. Grok 3 Mini charges $0.50/1M output tokens vs $0.50 for Grok 4.1 Fast.
Best Use Cases
Choose Grok 3 Mini when:
- • You're already using xAI's API ecosystem
- • You're running high-volume, latency-sensitive workloads
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
Pros and Caveats at a Glance
Grok 3 Mini
- • Input pricing: $0.30/M tokens
- • Output pricing: $0.50/M tokens
- • Context window: 128,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Higher input cost than Grok 4.1 Fast
- • Smaller context window than Grok 4.1 Fast
Grok 4.1 Fast
- • Input pricing: $0.20/M tokens
- • Output pricing: $0.50/M tokens
- • Context window: 2,000,000 tokens
- • Max output: 131,072 tokens
Watch out for
- • Trade-offs are minor in this matchup.
Try Different Scenarios
Use the calculator below to see how costs change with different usage patterns
Grok 3 Mini (xAI)
Grok 4.1 Fast (xAI)
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Sign Up for xAI →Frequently Asked Questions
Which is cheaper, Grok 3 Mini or Grok 4.1 Fast?▼
What is the context window difference between Grok 3 Mini and Grok 4.1 Fast?▼
Which model is better for AI Agent / Agentic Workflows?▼
Which model has better overall pricing for heavy usage?▼
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