LLM Reference

Grok 4 Models by xAI

xAIProprietary
13 models2025–2026Up to 2m ctxFrom $0.2/1M input

Details

ResearcherxAI
LicenseProprietary
Commercial useCommercial use: conditional
Models13
Released2025–2026
Max context2m

Capabilities

Vision12 of 13 models
Multimodal12 of 13 models
Reasoning10 of 13 models
Function Calling10 of 13 models
Tool Use10 of 13 models
Structured Outputs9 of 13 models
Code Execution1 of 13 models

About

Grok 4 is a family of 13 AI models by xAI, released between 2025 and 2026.

Current Variants

Use-when guidance is based on each model's tracked capabilities, context window, release date, and replacement status.

8 in view5 retired

Use when the workload needs code, 256k context, and reasoning.

2026-05code256k contextreasoning
Grok 4.3Current

Use when the workload needs 1m context, reasoning, and tool use.

2026-051m contextreasoningtool use

Use when the workload needs agentic, 2m context, and reasoning.

2026-03agentic2m contextreasoning

Use when the workload needs reasoning, 1m context, and tool use.

2026-03reasoning1m contexttool use

Use when the workload needs 1m context, tool use, and function calling.

2026-031m contexttool usefunction calling
Grok 4.20Current

Use when the workload needs 1m context, reasoning, and tool use.

2026-021m contextreasoningtool use
Grok 4.1Current

Use when the workload needs 131k context, reasoning, and tool use.

2025-11131k contextreasoningtool use

Use when the workload needs 256k context and multimodal inputs.

2025-07256k contextmultimodal inputs

Release Timeline

7 release groups
2026-05
2 current
Grok 4.3
1m contextreasoningtool use
Current
Grok Build 0.1
code256k contextreasoning
Current
2026-03
3 current
Grok 4.20 Multi-Agent
agentic2m contextreasoning
Current
Grok 4.20 Non-Reasoning
1m contexttool usefunction calling
Current
Grok 4.20 Reasoning
reasoning1m contexttool use
Current
2026-02
1 current
Grok 4.20
1m contextreasoningtool use
Current
2025-11
1 current · 1 retired
Grok 4.1
131k contextreasoningtool use
Current
Grok 4.1 Fast
2m contextreasoningtool use
Replaced
2025-09
2 retired
Grok 4 Fast Non-Reasoning
2m contextreasoningmultimodal inputs
Replaced
Grok 4 Fast Reasoning
2m contextreasoningmultimodal inputs
Replaced
2025-08
1 retired
Grok Code Fast 1
code262k context314B parameters
Replaced
2025-07
1 current · 1 retired
Grok 4
256k contextreasoningtool use
Replaced
Grok 4 Heavy
256k contextmultimodal inputs
Current

Replaced By

Keep for legacy integrations; evaluate Grok 4.3 before new work.

Keep for legacy integrations; evaluate Grok 4.3 before new work.

Keep for legacy integrations; evaluate Grok 4.3 before new work.

Keep for legacy integrations; evaluate Grok Build 0.1 before new work.

Keep for legacy integrations; evaluate Grok 4.3 before new work.

Specifications(13 models)

Grok 4 model specifications comparison
ModelReleasedContextParametersVisionMultimodalReasoningFn CallingTool UseStructured OutputsCode Exec
Grok Build 0.12026-05256kYesYesYesYesYesYesNo
Grok 4.32026-051m~0.5TYesYesYesYesYesYesNo
Grok 4.20 Multi-Agent2026-032mYesYesYesYesYesYesNo
Grok 4.20 Reasoning2026-031mYesYesYesYesYesYesNo
Grok 4.20 Non-Reasoning2026-031mYesYesNoYesYesYesNo
Grok 4.202026-021mYesYesYesYesYesYesNo
Grok 4.12025-11131kYesYesYesYesYesNoNo
Grok 4 Heavy2025-07256kYesYesNoNoNoNoNo

Pricing

Grok 4 model pricing by provider
ModelProviderInput / 1MOutput / 1MType
Grok Build 0.1xAI Console$1$2Serverless
Grok Build 0.1Vercel AI Gateway$1$2Serverless
Grok Build 0.1OpenRouter$1$2Serverless
Grok 4.20xAI Console$1.25$2.5Serverless
Grok 4.3xAI Console$1.25$2.5Serverless
Grok 4.20 Multi-AgentxAI Console$1.25$2.5Serverless
Grok 4.3OpenRouter$1.25$2.5Serverless
Grok 4.20OpenRouter$1.25$2.5Serverless
Grok 4.20 ReasoningxAI Console$1.25$2.5Serverless
Grok 4.20 Non-ReasoningxAI Console$1.25$2.5Serverless
Grok 4.20 Multi-AgentVercel AI Gateway$1.25$2.5Serverless
Grok 4.20 Non-ReasoningVercel AI Gateway$1.25$2.5Serverless
Grok 4.20 ReasoningVercel AI Gateway$1.25$2.5Serverless
Grok 4.3Vercel AI Gateway$1.25$2.5Serverless
Grok 4.3AWS Bedrock$1.25$2.5Serverless
Grok 4.20 Multi-AgentOpenRouter$2$6Serverless

Popular comparisons in this family

Frequently Asked Questions

What is Grok 4 used for?
Grok 4 is used for code, agentic, and reasoning. The family description and listed model capabilities point to those workloads as the best fit.
How does Grok 4 compare to Grok 1?
Grok 4 by xAI is strongest where you need code, while Grok 1 by xAI is the closest related family to check for reasoning. Grok 4 has 13 listed variants and reaches up to 2m context, so compare the specs and pricing tables before choosing a production model.
Which Grok 4 model should I use?
For the lowest listed input price, start with Grok 4.1 Fast through OpenRouter at $0.2/1M input tokens. For the most capable/latest local choice, evaluate Grok 4.20 Multi-Agent with 2m context and reasoning, tool use, function calling, structured outputs, and multimodal inputs.