Best Grok Models for OpenClaw — xAI's Grok 3 and Grok 3 Mini

The best Grok model for OpenClaw right now is Grok 3 Mini if you want the strongest balance of cost and reasoning, and Grok 3 if you need the full flagship context window and benchmark performance. Both models are available through the xAI API and through OpenRouter, making them straightforward to connect to OpenClaw.

Part of The Complete Guide to OpenClaw — the full reference covering setup, security, memory, and operations.

Why Grok for OpenClaw?

Grok is xAI's frontier model family, first released in beta in February 2025 with the Grok 3 announcement. The Grok 3 family stands out for OpenClaw operators because of its large context windows, competitive reasoning benchmarks, and straightforward API access that uses the OpenAI-compatible format.

For OpenClaw specifically, the two most relevant models are Grok 3 and Grok 3 Mini. Grok 3 gives you the largest context window in the family at 1 million tokens, which matters for long agent sessions, multi-tool workflows, and large document ingestion. Grok 3 Mini gives you a smaller but still practical 131K context window at roughly 10x lower cost per token.

As of April 2026, xAI has also released the Grok 4 family, but the Grok 3 models remain available and are often the better fit for OpenClaw operators who want proven performance without paying flagship Grok 4 pricing.

Grok Model Comparison for OpenClaw

Grok 3 and Grok 3 Mini target different operator profiles. The table below compares their key specs based on xAI's official models and pricing page.

For most OpenClaw operators, Grok 3 Mini is the practical default. The 131K context window is large enough for most agent workflows, and the cost difference is significant enough to matter over sustained use. Grok 3 makes sense when you are working with very large documents, long multi-step sessions, or when you need the absolute best reasoning quality the family offers.

xAI API Setup for OpenClaw

xAI's API is OpenAI-compatible, which means connecting it to OpenClaw requires the same configuration pattern as any other OpenAI-format provider. You need an API key from console.x.ai and the xAI base URL.

Set the following environment variables before starting OpenClaw:

export OPENAI_API_KEY="your-xai-api-key"
export OPENAI_BASE_URL="https://api.x.ai/v1"
export OPENAI_MODEL="grok-3-mini"

If you want to use the full Grok 3 model instead, change the model value:

export OPENAI_MODEL="grok-3"

For the thinking variants that expose chain-of-thought reasoning tokens, use grok-3-mini-fast or grok-3 with reasoning enabled. Check the xAI documentation for the latest model aliases, since xAI periodically updates which model ID maps to which version.

Connecting Grok via OpenRouter

OpenRouter provides access to Grok models without requiring a separate xAI account. As of April 2026, Grok 3 and Grok 3 Mini are both available on OpenRouter at the same pricing xAI charges directly, since OpenRouter does not mark up provider pricing.

To connect OpenClaw through OpenRouter:

export OPENAI_API_KEY="your-openrouter-api-key"
export OPENAI_BASE_URL="https://openrouter.ai/api/v1"
export OPENAI_MODEL="x-ai/grok-3-mini"

The advantage of OpenRouter is flexibility. If you already use OpenRouter for other models, you can switch between Grok, Claude, Gemini, and open-source models without changing your API key or base URL. For a detailed walkthrough, see the OpenClaw OpenRouter setup guide.

Strengths and Weaknesses

Grok 3's strongest benchmarks are in math and science reasoning. According to xAI's announcement, Grok 3 (Think) scored 93.3% on AIME 2025 and 84.6% on GPQA, placing it ahead of GPT-4o, Gemini 2.0 Pro, and DeepSeek V3 at the time of release.

Where Grok models shine for OpenClaw:

• Strong math and science reasoning for technical workflows
• 1 million token context window on Grok 3, useful for large codebases and long agent sessions
• Transparent reasoning tokens on Think variants, which help operators debug agent decisions
• OpenAI-compatible API, so no custom integration work is needed for OpenClaw

Where Grok models are weaker:

• Knowledge cutoff of November 2024, which means real-time information is not available through the base model
• Grok 3's $15.00 per million output tokens is expensive for high-volume agent work compared to alternatives like DeepSeek or Llama via Groq
• The model family is smaller than competing ecosystems, so there are fewer size options to tune cost and quality

Cost Breakdown

Grok 3 Mini is one of the more cost-efficient frontier API models for OpenClaw. The table below compares Grok models against common OpenClaw alternatives to put costs in perspective.

For operators running OpenClaw daily, Grok 3 Mini at $0.30/$0.50 is competitive with budget-tier cloud models while still delivering frontier-class reasoning on most tasks. The full Grok 3 is priced at the same tier as Claude Sonnet and GPT-4o, so it makes sense only when you specifically need the 1M context window or Grok's particular strengths in math and science.

For a broader cost breakdown across all providers, see How Much Does OpenClaw Cost.

Limitations and Tradeoffs

Grok models are strong options for OpenClaw, but they are not the right choice for every operator.

• No local option: Unlike Llama or Ollama-hosted models, Grok is only available through cloud APIs. If you need fully local, air-gapped operation, Grok is not an option. See the best Ollama models for OpenClaw instead.
• November 2024 knowledge cutoff: The base models do not have access to information after November 2024. For workflows that require current information, you will need to pair Grok with a search tool or live data source.
• Smaller model family: Compared to Meta's Llama or Alibaba's Qwen families, xAI offers fewer size and quantization options. You get Grok 3 or Grok 3 Mini, without the range of 8B/14B/32B/70B tiers that open-source families provide.
• Grok 3 output cost is high: At $15.00 per million output tokens, extended agent sessions with Grok 3 can get expensive. Use Grok 3 Mini for routine work and reserve the full model for tasks that specifically benefit from the larger context or stronger reasoning.

Related Guides

• OpenClaw xAI Grok Setup
• OpenClaw OpenRouter Setup
• Best Ollama Models for OpenClaw
• How Much Does OpenClaw Cost

FAQ

What is the best Grok model for OpenClaw in 2026?

Grok 3 Mini is the best default Grok model for OpenClaw because it offers strong reasoning at $0.30 per million input tokens with a 131K context window. Use the full Grok 3 only when you need the 1 million token context window or the highest benchmark scores.

How do I connect Grok to OpenClaw?

Set your OPENAI_API_KEY to your xAI API key, set OPENAI_BASE_URL to https://api.x.ai/v1, and set OPENAI_MODEL to grok-3-mini or grok-3. The xAI API is OpenAI-compatible, so no custom integration is needed.

Is Grok available on OpenRouter for OpenClaw?

Yes. As of April 2026, both Grok 3 and Grok 3 Mini are available on OpenRouter at the same pricing xAI charges directly. Use the model ID x-ai/grok-3-mini or x-ai/grok-3 with your OpenRouter API key.

How does Grok 3 compare to GPT-4o for OpenClaw?

Grok 3 matches or beats GPT-4o on math (AIME 2025: 93.3%) and science (GPQA: 84.6%) benchmarks, and offers a larger 1M context window versus GPT-4o's 128K. Pricing is comparable at the flagship tier. For budget use, Grok 3 Mini at $0.30/$0.50 is significantly cheaper than GPT-4o at $2.50/$10.00.

Can I run Grok models locally for OpenClaw?

No. Grok models are only available through xAI's cloud API or third-party providers like OpenRouter. If you need local models for OpenClaw, consider Llama, Qwen, or GLM models through Ollama instead.