grok-4-1-fast-reasoning

reasoningdeprecatedproprietary
Context
2M
Input price
$0.2/1M tokens
Output price
$0.5/1M tokens

Capabilities

Reasoning & Interaction
Reasoning
Tool Calling
Output Control
Structured Output
JSON Mode
Infrastructure
Streaming
Batch Processing

Details

Provider xAI
Creator xai
Familygrok-4
Licenseproprietary
Statusdeprecated
Typereasoning
Input modalitiestext, image
Output modalitiestext
Open weightNo
Parameters—
Architecture—
Context window2M tokens
Max input—
Max output—
Reasoning tokensYes
Knowledge cutoff
Release date
Sourceofficial

Tools

Function Callingfunction_calling
Call external functions and APIs

Pricing

Input
$0.2
Output
$0.5
Cache write
—
Cache read
$0.05
Batch in
—
Batch out
—

Family Comparison: grok-4

ModelContextMax outPricing
grok-4-1-fast-non-reasoning2M—$0.2$0.5
grok-4-1-fast-reasoning2M—$0.2$0.5
grok-4-fast-non-reasoning2M—$0.2$0.5
grok-4-fast-reasoning2M—$0.2$0.5
grok-4-0709256K—$3$15

API

GET/v1/models/xai/grok-4-1-fast-reasoning

grok-4-1-fast-reasoning

deprecated
Changes · 10 entries
grok-4-1-fast-reasoningupdateca7a400Nov 2, 2026, 03:02 AM
statusdeprecated
grok-4-1-fast-reasoningupdate73d11c6May 18, 2026, 03:39 AM
statusdeprecated
grok-4-1-fast-reasoningupdate3e56cf1Apr 26, 2026, 07:23 PM
page_urlhttps://docs.x.ai/docs/models#grok-4-1-fast-reasoning→https://docs.x.ai/developers/models/grok-4-1-fast-reasoning
statusdeprecated
grok-4-1-fast-reasoningupdate6a1e7e3Apr 24, 2026, 02:41 AM
statusdeprecated
grok-4-1-fast-reasoningupdatefa2bbbbMar 24, 2026, 05:22 AM
capabilitiesbatchyesvisionyes
grok-4-1-fast-reasoningupdate1cd659eMar 24, 2026, 04:19 AM
capabilitiesjson modeyes
grok-4-1-fast-reasoningupdateb301ebeMar 23, 2026, 11:47 PM
knowledge_cutoff2024-11
grok-4-1-fast-reasoningupdate2b100acMar 23, 2026, 05:30 AM
licenseproprietary
page_urlhttps://docs.x.ai/docs/models#grok-4-1-fast-reasoning
open_weightno
tools["function_calling"]
grok-4-1-fast-reasoningupdate7a4f1f6Mar 22, 2026, 05:43 AM
model_typereasoning
grok-4-1-fast-reasoningcreate7f5c66fMar 21, 2026, 05:16 AM