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Grok 4.20 Beta 0309 Reasoning

xAI

At a glance

Price per 1M tokens (input)
$1.25
Price per 1M tokens (output)
$2.50
Context
1,000,000 tokens
Free access
yes (see below)

Refreshed daily; data verified August 16, 2026. Published August 12, 2026, last price change August 12, 2026.

Grok 4.20 Beta 0309 Reasoning is built for technical teams and analysts who need a model that can inspect images, invoke external tools, and walk through multi-step problems with visible logic. It suits tasks like document analysis, workflow automation, and complex troubleshooting where you need both visual context and structured decision-making. The vendor's approach emphasizes transparency through step-by-step reasoning and practical integration via tool calling, which lets the model interact with APIs or databases. This model is a good fit for developers and operations staff who want to embed a reasoning layer into their existing systems.

Specifications & pricing

Input (per 1M tokens)$1.25
Output (per 1M tokens)$2.50
Cache read (per 1M tokens)$0.20
Context window1,000,000 tokens
Max output1,000,000 tokens
Capabilitiesimages, tool calling, reasoning

LiteLLM community dataset (MIT), verified August 16, 2026. Official xAI pricing.

What Grok 4.20 Beta 0309 Reasoning would cost on your workload — run it through the cost calculator →

Price history

DateInput / 1MOutput / 1M
August 9, 2026 (first record)$2.00$6.00
August 12, 2026$1.25$2.50

Where to try Grok 4.20 Beta 0309 Reasoning for free

  • xAI offers a free chat — Grok (limited free access). A vendor's free chat may run a different model from the same family — the exact model is not guaranteed.

Frequently asked questions

What is this model best used for in a business setting?+

It excels at tasks that combine visual data with logical analysis, such as reviewing diagrams or screenshots, then executing a series of actions via tool calling. Common uses include automated document triage, incident response where you need to reason through logs and images, and building custom assistants that can query internal systems. The step-by-step reasoning also helps with auditability, as you can trace how the model reached a conclusion.

How do I get started with Grok 4.20 Beta 0309 Reasoning?+

You can access it through the xAI API or a supported cloud platform. Start by testing with simple prompts that combine an image and a question, then gradually add tool definitions for your own functions. The model supports standard function calling, so you can define tools in JSON schema and let the model decide when to call them. Review the official documentation for authentication and endpoint setup.

How does this model differ from other Grok models in the line?+

The key difference is the explicit reasoning mode and enhanced tool use. While other Grok variants focus on conversational fluency or speed, this beta version is tuned for tasks that require deliberate, transparent problem-solving. It also has stronger image understanding compared to text-only siblings, making it suitable for multimodal workflows. However, it may be slower due to the reasoning steps, so it is not ideal for real-time chat where low latency is critical.

What are the main limitations I should know about?+

The reasoning process can be verbose, which increases response time and computational cost. Image understanding is robust but not perfect for very small text or heavily distorted visuals. Tool calling requires careful setup—you must define tools accurately and handle errors gracefully. Also, as a beta, behavior may change between releases, so test thoroughly before deploying in production.

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