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 — 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.