xAI has published downloadable weights for two Grok models: Grok-1, a 314 billion parameter Mixture-of-Experts model released under the Apache 2.0 license in March 2024, and Grok 2, uploaded to Hugging Face on August 22, 2025 under a custom Grok 2 Community License. As of October 27, 2026, the xai-org account on Hugging Face lists only those two models. The Grok chatbot that people use on X and in the Grok app is a separate hosted service, and later versions have not been published as weights.
Key takeaways
- Grok-1 uses 8 experts with 2 active per token, 64 layers, and a context length of up to 8,192 tokens, according to its repository.
- The Grok 2 download is roughly 500 GB across 42 files, and its checkpoint is built for 8 GPUs with more than 40 GB of memory each.
- The two releases carry different licenses: Apache 2.0 for Grok-1, and a custom community license with limits for Grok 2.
- A public statement from August 2025 said Grok 3 would be open-sourced in about six months, and no Grok 3 weights appear on the Hugging Face listing.
What "open weights" means here
A weights release gives developers the trained numerical parameters of a model, which they can run on their own hardware. It does not include the training data, the full training pipeline, or the hosted product with its moderation layers and live data access. The Grok-1 repository states this scope directly: its license covers the source files in the repository and the Grok-1 weights. The repository's own mixture-of-experts code was written to check correctness and is not optimized for speed.
Open weights are not the same as open source in the sense of the Open Source Initiative. Whether a release counts as open depends on the license, which is why the two Grok releases differ.
Grok-1: the architecture on record
The Grok-1 repository on GitHub lists the specifications in the table below. The figures come from the repository README.
| Item | Value |
|---|---|
| Total parameters | 314 billion |
| Architecture | Mixture of 8 experts, 2 active per token |
| Layers | 64 |
| Attention heads | 48 for queries, 8 for keys and values |
| Embedding size | 6,144 |
| Vocabulary | 131,072 tokens, SentencePiece tokenizer |
| Context length | Up to 8,192 tokens |
| License | Apache 2.0 (code and weights) |
A mixture-of-experts design routes each token through a small subset of the network, so only part of the 314 billion parameters does work for any one token. Running the model still needs enough GPU memory to hold the checkpoint, which the README describes as very large.
Grok 2: what the Hugging Face repository shows
The xai-org/grok-2 repository shows its first commit on August 22, 2025, followed by large-folder uploads within the hour and a series of README, configuration, and license edits on August 23 and 24. A further license edit is dated November 5, 2025. The model card describes the contents as the weights of Grok 2, a post-trained model xAI trained and used in 2024, and notes that it requires a specific chat template.
The card lists a download of about 500 GB in 42 files. Its serving example uses the SGLang inference engine, version 0.5.1 or later, with tensor parallelism of 8 and fp8 quantization, which means 8 GPUs, each with more than 40 GB of memory. That puts local use beyond ordinary desktop hardware and within reach of research groups and companies with GPU servers. In his announcement, Elon Musk called the model Grok 2.5, while the repository is named grok-2, so press coverage uses both names for the same release.
How the two licenses differ
The current text of the Grok 2 license is posted in the repository. The table summarizes it in plain terms and is not legal advice.
| Question | Grok-1 | Grok 2 |
|---|---|---|
| License | Apache 2.0 | Grok 2 Community License Agreement |
| Commercial use | Allowed under Apache terms | Allowed if the user and affiliates follow xAI's Acceptable Use Policy |
| Training other models on outputs | No such clause in the repository | Barred for foundational, large language, or general-purpose models, with an exception for permitted fine-tuning of the Grok materials |
| Attribution | Apache notice requirements | Include the agreement and display "Powered by xAI" when distributing |
| Revocable | No | Described as revocable, and ends on breach |
The Grok 2 text also ends the license if the user sues anyone claiming the materials infringe intellectual property, unless the suit answers one filed first, and sets Texas law with courts in Tarrant County. A company planning to build on the weights would want its own counsel to read the full license.
The Grok 3 statement
When the Grok 2 weights appeared, Musk wrote in a post that Grok 3 would be made open source in about six months. About 14 months have passed, and the xai-org Hugging Face page, checked on October 27, 2026, shows only grok-2 and grok-1 as models. Not seeing a release on that page does not prove none exists elsewhere, and xAI has not been shown here to have announced a schedule change.
A short checklist before downloading weights
- Read the license in the repository, not a summary, and note its date or last edit.
- Check the hardware figures against the checkpoint format, since the Grok 2 card assumes 8 GPUs.
- Confirm which model version the weights represent. The Grok 2 weights describe a model trained and used in 2024, not the chatbot of today.
- Check for a required chat template or serving engine version.
- Review the terms on outputs if the plan involves training another model.
FAQ
Is Grok open source?
Partly. Grok-1 is under Apache 2.0, while Grok 2 uses a custom license with restrictions. Newer Grok models are offered as hosted services.
Can the Grok 2 weights run on a laptop?
Not in the form published. The model card describes a roughly 500 GB checkpoint prepared for 8 GPUs of more than 40 GB each.
Was Grok 2 released as Grok 2.5?
The repository is named grok-2. Musk's post used the name Grok 2.5 for the release, so both names circulate.
Are the weights the same as the chatbot on X?
No. The published weights are an older model, and the chatbot is a hosted product that changes over time.
Related reading
- The Grok chatbot and its tone
- Baidu's Ernie Bot
- Chai and AI companion chat
- The history of conversational interfaces
More in AI Tools and Industry.
Last verified: October 2026
Sources
- grok-1 repository README, xAI (xai-org), GitHub, 2024
- grok-2 model card, commit history, and license, xai-org, Hugging Face, 2025
- xai-org organization page, Hugging Face, accessed October 27, 2026
- Post on the Grok 2.5 release and Grok 3 plans, Elon Musk, X, August 2025