xAI: grok-4.20-reasoning:free

Name: grok-4.20-reasoning:free
Brand: xAI

grok-4.20-reasoning:free

262K context2M outReasoningToolsFilesCacheStructuredWeb search

Released Mar 31, 2026Knowledge cutoff 2025Updated Mar 31, 2026

Grok 4.20 is a reasoning model from xAI with industry-leading speed and agentic tool calling capabilities. It combines the lowest hallucination rate on the market with strict prompt adherance, delivering consistently precise and truthful responses. Reasoning can be enabled/disabled using the reasoning enabled parameter in the API. Learn more in our docs

Mode chatTokenizer Grok

All providers for this model are busy right now

Every upstream provider has hit its rate limit. The model comes back automatically once limits lift, usually within hours. Try again in a little while or switch to another model.

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Pricing

Input price

$0.00/ 1M tokens

Output price

$0.00/ 1M tokens

Context window 262K tokensCompatible endpoints openaiVendor xAI

Performance

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Supported parameters

All providers = every upstream serving this model supports it. Some providers = depends on which upstream handles the request. Default = the value sent when you leave the parameter unset.

Parameter	Providers	Default
frequency_penalty	Some providers	Not sent by default
include_reasoning	All providers	-
logprobs	All providers	-
max_tokens	All providers	-
presence_penalty	Some providers	Not sent by default
reasoning	All providers	-
repetition_penalty	Some providers	Not sent by default
response_format	All providers	-
seed	All providers	-
structured_outputs	All providers	-
temperature	All providers	Not sent by default
tool_choice	All providers	-
tools	All providers	-
top_k	Some providers	Not sent by default
top_logprobs	All providers	-
top_p	All providers	Not sent by default

Frequently asked questions

How much does grok-4.20-reasoning:free cost per 1M tokens?

Input is priced at $0.00 per 1M tokens, output at $0.00 per 1M tokens. Billing is per token, no rounding to batch sizes.

How do I access grok-4.20-reasoning:free via API?

Send requests to the UnoRouter /v1/chat/completions endpoint with model=grok-4.20-reasoning:free. Any OpenAI-compatible client library works. Authentication uses a standard Bearer token.