# Grok 4 Heavy

Grok 4 Heavy is an AI model released by SpaceXAI on Jul 9 2025.

## Facts

| Field | Value |
| --- | --- |
| Model | Grok 4 Heavy |
| Developer | SpaceXAI |
| Release date | Wednesday, Jul 9 2025 |
| Licensing | Proprietary |

## Questions and answers

### When was Grok 4 Heavy released?

Grok 4 Heavy was released by SpaceXAI on Wednesday, Jul 9 2025.

### Who made Grok 4 Heavy?

Grok 4 Heavy was built by SpaceXAI. Elon Musk's AI company building the Grok series of models. Founded in 2023 as xAI, now part of SpaceX. Cursor (Anysphere) and its Composer coding models were acquired in 2026 and are tracked here.

### Is Grok 4 Heavy open source?

No. Grok 4 Heavy is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

### What came before and after Grok 4 Heavy?

SpaceXAI's previous tracked release was Grok 4 on Jul 9 2025. It was followed by Grok 2.5 on Aug 23 2025.


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Canonical page: https://aireleasetracker.com/model/xai/grok-4-heavy
Full dataset: https://aireleasetracker.com/llms-full.txt · JSON: https://aireleasetracker.com/models.json
Source: AI Release Tracker (https://aireleasetracker.com). Benchmark scores are the figures published by the releasing lab at launch.