Grok

grok-4.20-0309-reasoning

grok/grok-4.20-0309-reasoning

ChatVisionToolsSystem promptReasoning

Use this model

Context

Max output

64K

Input / 1M

$1.25

Output / 1M

$2.50

Cached / 1M

$0.20

Cutoff

unknown

About this model

Grok 4.20 (grok-4.20-0309-reasoning) is a high-performance xAI model with industry-leading speed, agentic tool calling, and a low hallucination rate with strict prompt adherence.

Best suited for

Agentic tool calling
Long-horizon reasoning
Low-hallucination document understanding

Built-in tools

Gtwy web search

Hosted by the gateway — enable them per request without wiring your own endpoint.

Capabilities

Vision

Accepts images alongside text in the same message.

Tools

Native function calling, so agents can invoke your endpoints.

System prompt

Honours a dedicated system role, separate from the user turn.

Reasoning

Emits a separate thinking pass before the answer.

Supported parameters

creativity_level

Controls the creativity of responses. Higher values (e.g., 0.7) increase creativity; lower values (e.g., 0.2) make responses more predictable.

max_tokensMax Tokens Limit

Specifies the maximum number of text units (tokens) allowed in a response, limiting its length.

parallel_tool_calls

Enables parallel execution of tools, allowing multiple tools to run simultaneously.

reasoning

Grok 4.20 always reasons before responding; effort level is not user-configurable per official docs.

response_type

Defines the format or type of the generated response.

stream

Sends the response in real-time as it's being generated.

tool_choice

Decides whether to use tools or just the model for generating responses.

tools

Lists tool definitions or capabilities available to the model.

Use this model

OpenAI-SDK compatible, with gateway fallback and routing across providers.

Other Grok models

Model	Context	Max output	Input	Output	Capabilities
grok-4.7 Chat	500K	64K	$2.00	$6.00	Vision, Files, Tools, System prompt, Reasoning
grok-build-0.1 Chat	256K	64K	$1.00	$2.00	Vision, Tools, System prompt, Reasoning
grok-4.20-multi-agent-0309 Chat	1M	64K	$1.25	$2.50	Vision, Tools, System prompt, Reasoning
grok-4.20-0309-non-reasoning Chat	1M	64K	$1.25	$2.50	Vision, Tools, System prompt
grok-4.6 Chat	500K	64K	$2.00	$6.00	Vision, Files, Tools, System prompt, Reasoning
grok-4.3 Chat	1M	64K	$1.25	$2.50	Vision, Tools, System prompt, Reasoning
grok-4.5 Chat	500K	64K	$2.00	$6.00	Vision, Tools, System prompt, Reasoning

Pricing & provider details

Grok

grok/grok-4.20-0309-reasoning

Input · per 1M: $1.25
Output · per 1M: $2.50
Cached input · per 1M: $0.20
Context window: 1,000,000 tokens
Max output: 64,000 tokens
Knowledge cutoff: unknown
Auto-router: Not supported

Start building today

Route grok-4.20-0309-reasoning — and every other model in the catalogue — through one endpoint, with failover built in.

Get started freeAll models