Grok 4.1 Fast
Pricing & Specs
xAI · $0.2 input / $0.5 output per 1M tokens · 2M context window
The per-token price never tells the full story. A typical task (1K input + 500 output tokens) on Grok 4.1 Fast costs about $0.0004, roughly $0.45 per 1,000 runs. But if it needs 3x the tokens of a cheaper model to match quality on YOUR task, the economics flip. The only way to know is to benchmark it on your actual workload.
Grok 4.1 Fast API Pricing
| Tokens | Price |
|---|---|
| Input | $0.2 / 1M tokens |
| Output | $0.5 / 1M tokens |
| Cached input | $0.05 / 1M tokens |
Cached input tokens are billed when caching is enabled.
What that means in practice
Grok 4.1 Fast Specs
| Spec | Value |
|---|---|
| Context window | 2M tokens |
| Input modalities | text, image |
| Output modalities | text |
| Latency (measured by OpenMark) | ~1.4s median response |
| Reasoning model | Yes |
| Tool / function calling | Yes |
| JSON mode | Yes |
| Streaming | Yes |
| Prompt caching | Yes |
| Batch API | No |
FAQ
How much does Grok 4.1 Fast cost?
Grok 4.1 Fast costs $0.2 per 1M input tokens and $0.5 per 1M output tokens ($0.05 per 1M cached input tokens).
What is Grok 4.1 Fast's context window?
Grok 4.1 Fast has a 2M-token context window.
Can I test Grok 4.1 Fast on my own task?
Yes. OpenMark lets you benchmark Grok 4.1 Fast against 100+ models on your own task with real API calls, with no API keys needed, free tier available.
Is Grok 4.1 Fast the right model for YOUR task?
Pricing tables can't answer that. Benchmark it against 100+ models
on your actual workload: real API calls, real costs. Free tier available.