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Grok 4 Fast
xai·xai/grok-4-fast-2·Deprecated·Closed
Fast Grok model for responsive chat, reasoning, and tool-assisted work
At a glance
Reference price$0.20 / $0.50 per 1M
Cache read $0.05 · ZenMux
Lowest paid$0.20 / $0.50
ZenMux Gateway
Context2,000,000
Output limit64,000
Capabilities
✓ Reasoning✓ Tool use? Structured output✓ Temperature✓ Attachments
Modalities
TextImage
Knowledge cutoff2025-01-01
Released / updated2025-09-19 / 2025-09-19
Quality & performanceArtificial Analysis · Intelligence Index v4.1 · rep. tier Reasoning
Intelligence27.9
Value101
Coding—
Agentic—
Output speed—
TTFT—
Value formulaIQ 27.9 ÷ min blended $0.275 = 101
Reasoning tier → intelligence / speed (higher tier = stronger but slower)
Non-reasoningIQ 16.6
ReasoningIQ 27.9
Quality is independently evaluated by Artificial Analysis. Speed/latency are model-level medians.
Available at 1 providers1 with public prices
| Provider | Tier | Input | Output | Cache read | Cache write | Context | Output limit | Status |
|---|---|---|---|---|---|---|---|---|
| ZenMux x-ai/grok-4-fast | Gateway | $0.20 | $0.50 | $0.05 | — | 2,000,000 | 64,000 | deprecated |
Sorted by blended price (input×0.75 + output×0.25) asc. The official channel always shows regardless of rank. Whether a gateway's low price is actually usable can't be verified.
Your usage cost
1ZenMux$47.00
The cheapest paid channel is the only channel.
Benchmark
No upstream benchmark data for this model. For quality, see the Artificial Analysis intelligence score above.
Reasoning control
Toggle (on / off)
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Price historyone sample accumulated per data sync
Input listOutput listMin blended