Grok 4 Fast is xAI's language model with a 131K context window and up to 30K output tokens, available from 2 providers, starting at $0.2 / 1M input and $0.5 / 1M output. A cost-efficient multimodal LLM from xAI with a 2M token context window, available in both reasoning and non-reasoning flavors.
Specifications
Canonical IDxai-grok-4-fast
TypeLanguage
StatusDeprecated
CreatorxAIxAI
Providers
Context Window131K tokens
Max Output30K tokens
Input ModalitiesImageText
Output ModalitiesText
Reasoning Effortsdefault
Release Date · 11 months ago
Knowledge Cutoff · 11 months ago
Deprecation Date
Benchmarks
Intelligence Index
16.6
#225
Math Index
41.3
#148
MMLU-Pro
0.7
#183
GPQA
0.6
#284
HLE
0.0
#356
LiveCodeBench
0.4
#169
IFBench
0.4
#265
Time to First Token
0.00s
#367
SciCode
0.3
#231
AIME 2025
0.4
#148
LCR
0.2
#279
TerminalBench Hard
0.1
#190
TAU2
0.6
#154
Output TPS
0.0
#489

Capabilities

Input2/5
Text
Image
Audio·
Video·
PDF·
Output1/5
Text
Image·
Audio·
Video·
Embedding·
Capabilities4/13
Reasoning
Adaptive Reasoning·
Function Calling
Parallel Function Calling·
Structured Outputs
Native JSON Schema
Web Search·
URL Context·
Computer Use·
Code Execution·
File Search·
Prompt Caching·
Assistant Prefill·

Pricing by Provider

US Dollar ($)
Per 1M tokens
ProviderStandard
Input
$ / 1M
Output
$ / 1M
Azure AI Foundry logo
Azure AI Foundry
xai:grok4fast
$0.2$0.5
Oracle Cloud (OCI) logo
Oracle Cloud (OCI)
oci/xai.grok-4-fast
$5.00$25.00

Cost Calculator

US Dollar ($)
Preset:

Versions

VersionReleasedContextInput / 1MOutput / 1MStatus
Grok 4.5500K$2.00$6.00Available
Grok 4.31.0M$1.25$2.50Available
Grok 4.202.0M$1.25$2.50Available
Grok 4.20 Multi-Agent2.0M$1.25$2.50Available
Grok 4.20 Multi-Agent Beta2.0M$1.25$2.50Available
Grok 4.20 Non-Reasoning2.0M$1.25$2.50Available
Grok 4.20 Reasoning2.0M$1.25$2.50Available
Grok 4.1 Reasoning2.0M$0.200$0.500Deprecated
Grok 4.1 Fast2.0M$0.200$0.500Deprecated
Grok 4.1 Fast Non-Reasoning2.0M$0.200$0.500Deprecated
Grok 4 Fast131K$0.200$0.500Current

Model IDs

grok-4-fast
oci/xai.grok-4-fast
x-ai/grok-4-fast
xai-grok-4-fast