Grok 4 Fast
xAI deprecatedUpdated July 2026. Grok 4 Fast by xAI: $0.2/M cache-miss input, $0.5/M output tokens. 2.0M context, 33K max output. Function Calling. Free calculator + compare 40+ models.
Input Price
$0.2
cache miss / 1M tokens
Output Price
$0.5
per 1M tokens
Context Window
2.0M
tokens
Specifications
| Provider | xAI |
| Model ID | grok-4-fast |
| Input Price | $0.2 / 1M cache-miss tokens |
| Output Price | $0.5 / 1M tokens |
| Context Window | 2.0M tokens |
| Max Output | 33K tokens |
| Capabilities | textfunction_calling |
| Release Date | 2025-07 |
| Pricing Source | Official xAI pricing |
| Price Verified | 2026-07-14 · Grok 4.5, Grok 4.3, Grok 4.20, and Grok Build pricing was refreshed from the xAI pricing table. |
| Notes | Retired alias. Calls route to the current Grok model family and use current pricing. |
Monthly Cost Estimates
Estimated monthly costs based on different daily usage levels (assuming 50% input / 50% output split). Input estimates use cache-miss pricing, so cache-heavy workloads can be lower.
| Daily Tokens | Monthly Cost | Annual Cost |
|---|---|---|
| 10K | $0.105 | $1.26 |
| 50K | $0.525 | $6.30 |
| 100K | $1.05 | $12.60 |
| 500K | $5.25 | $63.00 |
| 1.0M | $10.50 | $126.00 |
About Grok 4 Fast
Grok 4 Fast is a large language model by xAI. It features a 2.0M token context window with up to 33K tokens of output per request. The model supports 2 capabilities: text, function_calling.
At $0.2 per million cache-miss input tokens and $0.5 per million output tokens, Grok 4 Fast is positioned as a cost-effective option in the xAI lineup. Use our Token Counter to estimate how many tokens your prompts use, and our Pricing Calculator to compare costs across all models.
Grok 4 Fast Key Details
- Pricing: $0.2/M cache-miss input tokens, $0.5/M output tokens
- Context window: 2.0M tokens — one of the largest available
- Max output: 33K tokens per response
- Capabilities: text, function_calling
- Highlights: Retired alias. Calls route to the current Grok model family and use current pricing.
- Released: 2025-07
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FAQ
How much does Grok 4 Fast cost?
Grok 4 Fast costs $0.2 per million cache-miss input tokens and $0.5 per million output tokens. For a typical workload of 100K input tokens/day and 50K output tokens/day, expect approximately $1.35/month before cache-hit savings.
What is Grok 4 Fast's context window?
Grok 4 Fast supports a context window of 2.0M tokens. This means your combined input prompt and output response can be up to 2.0M tokens. The maximum output per response is 33K tokens.
Is Grok 4 Fast good for my use case?
Grok 4 Fast supports text, function_calling. As a budget-friendly model, it works well for high-volume tasks like classification, summarization, and simple generation. Use our Pricing Calculator to compare with alternatives.