Codex Mini vs Grok 4.20

Compare OpenAI and xAI AI models

OpenAI

Codex Mini

xAI

Grok 4.20

Try OpenAI →Try xAI →

Cost Comparison (1000 input + 500 output tokens, 100 requests/day)

Codex Mini

Per Request:$0.004500

Daily:$0.45

Monthly:$13.50

Yearly:$164.25

Grok 4.20

Per Request:$0.005000

Daily:$0.50

Monthly:$15.00

Yearly:$182.50

Cost Differences

+$0.000500

Per Request

+$0.05

Daily

+$1.50

Monthly

+$18.25

Yearly

Grok 4.20 costs more than Codex Mini

Feature Comparison

Feature	Codex Mini	Grok 4.20
Provider	OpenAI	xAI
Input Price	$1.50/1M tokens	$2.00/1M tokens
Output Price	$6.00/1M tokens	$6.00/1M tokens
Context Window	200,000 tokens	2,000,000 tokens
Max Output	32,768 tokens	131,072 tokens
Category	efficient	reasoning
Capabilities	textcodereasoning	textvisionreasoningcode
Release Date	2/2/2026	2/17/2026

Codex Mini vs Grok 4.20: Which Should You Choose?

Choosing between Codex Mini and Grok 4.20 depends on your priorities: cost efficiency, context length, or raw capability. Codex Mini is the more affordable option at $1.50/1M input tokens — 25% cheaper than Grok 4.20. Meanwhile, Grok 4.20 offers a significantly larger context window at 2,000,000 tokens vs 200,000 for Codex Mini.

These models come from different providers — OpenAI and xAI — which means different API ecosystems, SDKs, rate limits, and terms of service. If you're already integrated with OpenAI, switching to xAIinvolves migration effort beyond just pricing. Factor in your existing infrastructure when deciding.

These models target different tiers: Codex Mini is a efficient model while Grok 4.20 is reasoning. This means they're optimized for different workloads. Grok 4.20 targets more demanding workloads, while Codex Mini provides a cost-effective option for everyday tasks.

Output costs matter too. Codex Mini charges $6.00/1M output tokens vs $6.00 for Grok 4.20.

Multimodal capabilities: Grok 4.20 supports vision (image inputs) while Codex Mini is text-only. If your application needs image understanding, this narrows your choice.

Best Use Cases

Choose Codex Mini when:

• Budget is a primary concern
• You're already using OpenAI's API ecosystem
• You're running high-volume, latency-sensitive workloads

Choose Grok 4.20 when:

• You need a larger context window (2,000,000 tokens)
• You need more capabilities (vision)
• You need longer outputs (up to 131,072 tokens)
• You're already using xAI's API ecosystem

Try Different Scenarios

Use the calculator below to see how costs change with different usage patterns

Codex Mini (OpenAI)

Cost Calculator

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Model

Input Tokens

Output Tokens

Requests/Day

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Grok 4.20 (xAI)

Cost Calculator

Provider

Model

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Start using Codex Mini today

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Frequently Asked Questions

Which is cheaper, Codex Mini or Grok 4.20?▼

Codex Mini is cheaper for input tokens at $1.50 per million tokens vs $2.00 for Grok 4.20 — that's 25% savings on input costs.

What is the context window difference between Codex Mini and Grok 4.20?▼

Codex Mini supports 200,000 tokens while Grok 4.20 supports 2,000,000 tokens — a difference of 1,800,000 tokens in favor of Grok 4.20.

Which model is better for AI Agent / Agentic Workflows?▼

Both models support text, code, reasoning. For ai agent / agentic workflows, Codex Mini is the lower-cost option, while Grok 4.20 offers a larger context window (2,000,000 vs 200,000 tokens). Choose Codex Mini for budget sensitivity or Grok 4.20 for longer context tasks.

Which model has better overall pricing for heavy usage?▼

At 100 requests/day with 1,000 input and 500 output tokens each, Codex Mini costs about $13.50/month and Grok 4.20 costs about $15.00/month. Overall, Codex Mini has lower combined input + output rates ($1.50 in, $6.00 out) vs Grok 4.20.