How much does Grok 4.1 Fast cost?

Grok 4.1 Fast is billed per token: $0.2 per million input tokens and $0.5 per million output tokens. Cached input reads cost $0.05 per million tokens.

What is the Grok 4.1 Fast context window?

Grok 4.1 Fast accepts up to 2,000,000 tokens of context and can return up to 16,384 output tokens per request.

Is Grok 4.1 Fast cheaper than other xAI models?

Grok 4.1 Fast is the cheapest xAI model we track on input tokens, across 3 models.

Does Grok 4.1 Fast support image input?

Yes. Grok 4.1 Fast supports image input, tool use, long context.

Has Grok 4.1 Fast pricing changed recently?

No. Grok 4.1 Fast pricing has been stable across every weekly snapshot we've recorded.

Grok 4.1 Fast Pricing

xAI · Grok 4 · Live

Prices verified July 29, 2026

Grok 4.1 Fast costs $0.2 per million input tokens and $0.5 per million output tokens on the xAI API. Cached input reads are billed at $0.05 per million tokens. It supports a 2,000,000-token context window and up to 16,384 output tokens per request. The model supports image input, tool use, long context. Pricing verified July 29, 2026.

Grok 4.1 Fast API pricing

Input (per 1M tokens): $0.2
Output (per 1M tokens): $0.5
Cached input (per 1M tokens): $0.05
Context window: 2,000,000 tokens
Max output: 16,384 tokens

Estimate your Grok 4.1 Fast cost

Capabilities

Image inputTool useLong context

Price history

Price-stable since June 28, 2026.

Source: SaaS Price Hub · verified daily

Frequently asked questions

Notes

Fast variant optimized for high throughput. Among the cheapest frontier-adjacent options on the market at $0.20/M input. Cached input drops to $0.05/M with prompt caching enabled. [2026-07-12] Context Window updated 1,000,000 → 2,000,000 per multiple corroborating sources (x.ai news, datastudios.org, Oracle OCI docs, mindstudio.ai). Prices unchanged ($0.20/$0.50, cache read $0.05). CAUTION: one source reports an 8,000-token per-response cap vs 16,384 Max Output in table — unresolved, recheck next run. [2026-07-13] Prices re-verified unchanged ($0.20/$0.50, cache read $0.05) via mem0.ai + costgoat. Config conflict PERSISTS and widened: datastudios.org claims 128K context / 8,192 max output; aimlapi.com docs claim 2M context / 16K playground cap. Left 2M / 16,384 in place — needs manual check against docs.x.ai; recheck next run. [2026-07-27] Verification attempt produced no clear result — recheck next run. Search reports Grok 4.1 Fast is no longer listed on xAI's current public pricing page (possibly legacy/enterprise-only); no fresh price confirmation found. Prices untouched. Config conflict from prior runs still unresolved. Deprecation candidate — Khaled to decide. [2026-07-29] Prices re-verified unchanged ($0.20/$0.50) via developer.puter.com + benchlm.ai — first price confirmation since the 07-27 delisting concern. Model still not prominent on xAI's main pricing page; context/max-output config conflict from prior runs still unresolved (needs manual docs.x.ai check). Deprecation decision still with Khaled.