Grok 4.1 Fast

Ultra-cheap, large-context (2M) variant; among the lowest-priced frontier-adjacent APIs in 2026.

Grok 4.1 Fast strengths

• Extremely low cost
• 2M token context
• Fast latency
• Aggressive cache discount

Pricing & context

Cost guide: a typical call of about 10K input + 2K output tokens costs roughly $0.003 at list prices. Worth modelling against cheaper tiers before committing high-volume traffic.

When to choose Grok 4.1 Fast

Grok 4.1 Fast is best for large-context, high-volume agentic workloads where cost and context size dominate. If your workload is more cost-sensitive, weigh it against gpt-oss-120b (≈$0.03 input /1M) first.

Grok 4.1 Fast FAQ

How much does Grok 4.1 Fast cost?

Grok 4.1 Fast is priced at $0.20 ($0.05 cached) per 1M input tokens and $0.50 per 1M output tokens (public API list price), with a 2M tokens context window. A typical call of about 10K input and 2K output tokens costs roughly $0.003.

What is Grok 4.1 Fast best for?

Grok 4.1 Fast by xAI is best for large-context, high-volume agentic workloads where cost and context size dominate.

How does Grok 4.1 Fast pricing compare to Gemini 3.5 Flash-Lite?

Grok 4.1 Fast input costs $0.20 ($0.05 cached) per 1M tokens versus $0.30 for Gemini 3.5 Flash-Lite, roughly 1.5x less expensive on input. Output is $0.50 vs $2.50.

Is Grok 4.1 Fast multimodal?

Grok 4.1 Fast supports text, image.

Tools that use Grok 4.1 Fast