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Grok 3 Mini vs Grok 4.1 Fast

Compare xAI and xAI AI models

xAI
Grok 3 Mini
vs
xAI
Grok 4.1 Fast

Cost Comparison (1000 input + 500 output tokens, 100 requests/day)

Grok 3 Mini

Per Request:$0.000550
Daily:$0.055
Monthly:$1.65
Yearly:$20.075

Grok 4.1 Fast

Per Request:$0.000450
Daily:$0.045
Monthly:$1.35
Yearly:$16.425

Cost Differences

$0.000100
Per Request
$0.010000
Daily
$0.30
Monthly
$3.65
Yearly

Grok 4.1 Fast costs less than Grok 3 Mini

Feature Comparison

FeatureGrok 3 MiniGrok 4.1 Fast
ProviderxAIxAI
Input Price$0.30/1M tokens$0.20/1M tokens
Output Price$0.50/1M tokens$0.50/1M tokens
Context Window128,000 tokens2,000,000 tokens
Max Output131,072 tokens131,072 tokens
Categoryefficientefficient
Capabilities
textreasoningcode
textreasoningcode
Release Date2/17/20251/15/2026

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 tokens33% 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

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)

Start using Grok 3 Mini today

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Start using Grok 4.1 Fast today

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Frequently Asked Questions

Which is cheaper, Grok 3 Mini or Grok 4.1 Fast?
Grok 4.1 Fast is cheaper for input tokens at $0.20 per million tokens vs $0.30 for Grok 3 Mini — that's 33% savings on input costs.
What is the context window difference between Grok 3 Mini and Grok 4.1 Fast?
Grok 3 Mini supports 128,000 tokens while Grok 4.1 Fast supports 2,000,000 tokens — a difference of 1,872,000 tokens in favor of Grok 4.1 Fast.
Which model is better for AI Agent / Agentic Workflows?
Both models support text, code, reasoning. For ai agent / agentic workflows, Grok 4.1 Fast is the lower-cost option, while Grok 4.1 Fast offers a larger context window (2,000,000 vs 128,000 tokens). Choose Grok 4.1 Fast for budget sensitivity or Grok 4.1 Fast for longer context tasks.
Which model has better overall pricing for heavy usage?
At 100 requests/day with 1,000 input and 500 output tokens each, Grok 3 Mini costs about $1.65/month and Grok 4.1 Fast costs about $1.35/month. Overall, Grok 4.1 Fast has lower combined input + output rates ($0.20 in, $0.50 out) vs Grok 3 Mini.

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