Pricing · xAI

Grok 4.20 (reasoning)

xAI's grok-4.20-0309-reasoning, 1M tokens of context. Every number on this page was read off xAI's own pricing page — never estimated, never recalled from memory.

How xAI describes it

“Grok 4.20 is a high-performance model with industry-leading speed and agentic tool calling capabilities.”

Pricing

Long-prompt tiers

Pricing changes above a prompt-size threshold. If your average request is near the boundary, the effective rate is not the headline rate.

At the calculator's starting volume, 1M input tokens and 200K output tokens with no cache hits, Grok 4.20 (reasoning) costs $1.75: $1.25 for input and $0.50 for output, at the prices above. Same formula as the calculator; change the volume there.

Where this price sits

$1.25 per 1M input tokens (for prompts under 200K tokens) is the 26th cheapest input price of the 67 current models with a verified price on this site, and the 2nd of xAI's 8. Output costs 2.0× the input price.

Other current models in the Grok family:

• Grok Build 0.1 256K tokens $1.00 in · $2.00 out
• Grok 4.3 1M tokens $1.25 in · $2.50 out
• Grok 4.20 (non-reasoning) 1M tokens $1.25 in · $2.50 out
• Grok 4.20 Multi-agent 1M tokens $1.25 in · $2.50 out
• Grok 4.6 500K tokens $2.00 in · $6.00 out
• Grok 4.7 500K tokens $2.00 in · $6.00 out
• Grok 4.5 500K tokens $2.00 in · $6.00 out

Other price lists xAI publishes for Grok 4.20 (reasoning)

The prices above are xAI's Standard list, the one the table and the calculator use. xAI also sells Grok 4.20 (reasoning) on one other list, each with a condition. Figures and wording are quoted from xAI's own pages as read on the date shown; this site computes none of them.

• Batch · 20 % off all token types · wait: completion is best effort, most within 24 hours

  No figure shown: the per-model batch prices sit behind a toggle on each model's page that this site could not read without a browser, so no figure is shown.

  The Batch API lets you process large volumes of requests asynchronously at a discount to standard pricing. The size of the discount varies by model. The batch discount applies to all token types — input tokens, output tokens, cached tokens, and reasoning tokens.

  Source, read September 16, 2026

Specifications

Grok 4.20 (reasoning) was released on March 10, 2026.

Questions about Grok 4.20 (reasoning) pricing

How much does Grok 4.20 (reasoning) cost per million tokens?

$1.25 per 1M input tokens and $2.50 per 1M output tokens for prompts under 200,000 tokens, read on xAI's official pricing page on September 28, 2026.

What does a cached input token cost on Grok 4.20 (reasoning)?

$0.20 per 1M cached input tokens, 16% of the $1.25 input price.

Does Grok 4.20 (reasoning) cost more for long prompts?

Yes. For prompts of 200,000 tokens or more it costs $2.50 per 1M input tokens and $5.00 per 1M output tokens, $0.40 for cached input, against $1.25 and $2.50 below that.

Verified September 28, 2026 against xAI's official pricing page. Confidence: confirmed. No price change recorded for this model. How the data is checked.

Other xAI models with a verified price

• Grok Build 0.1 Grok $1.00 in · $2.00 out
• Grok 4.3 Grok $1.25 in · $2.50 out
• Grok 4.20 (non-reasoning) Grok $1.25 in · $2.50 out
• Grok 4.20 Multi-agent Grok $1.25 in · $2.50 out
• Grok 4.6 Grok $2.00 in · $6.00 out
• Grok 4.7 Grok $2.00 in · $6.00 out
• Grok 4.5 Grok $2.00 in · $6.00 out

Cheaper or equally priced alternatives

Current models with an input price at or below $1.25 per 1M tokens.

• Gemini 2.5 Pro Google $1.25 in · $10.00 out
• Grok 4.3 xAI $1.25 in · $2.50 out
• Grok 4.20 (non-reasoning) xAI $1.25 in · $2.50 out
• Grok 4.20 Multi-agent xAI $1.25 in · $2.50 out

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