xAI released Grok 4 and the multi-agent Grok 4 Heavy on July 9, 2025, alongside a $300-per-month SuperGrok Heavy plan. This guide covers its features, xAI-reported benchmarks, and the newer Grok 4.x models available as of September 2026.
Grok 4 is the xAI model announced on July 9, 2025 ↗. It launched in two variants: standard Grok 4 and Grok 4 Heavy, which runs multiple agents in parallel on the same problem. As of September 2026, xAI has since released newer Grok 4.x models, covered below.
Grok 4 is an xAI reasoning model released in July 2025 in two variants: standard Grok 4, and Grok 4 Heavy, which uses parallel test-time compute so that multiple agents work on a problem at once and compare answers.
Grok 4 launched as two distinct models. Standard Grok 4 is a reasoning model with native tool use and real-time search, according to xAI. Grok 4 Heavy considers multiple hypotheses in parallel, which xAI describes as progress on parallel test-time compute.
Elon Musk described Grok 4 Heavy's multi-agent setup as working like a "study group": several agents tackle the problem, then compare their answers to choose the best one, TechCrunch reported ↗. xAI positions this as the higher-accuracy option for hard problems.
At launch, Grok 4 was available through SuperGrok, X Premium+ and the xAI API. As of September 2026, the original grok-4 model is no longer listed in xAI's API model docs or on OpenRouter; both list newer models such as grok-4.7 instead. The xAI models page ↗ contains current API details.
Grok 4 offers native tool use with real-time search, including X data, plus xAI-reported results such as 61.9% on USAMO 2025 for Grok 4 Heavy. At launch, xAI said a coding model, a multimodal agent and video generation would follow.
Grok 4 can search the web and X in real time as a tool, so it can include current events and trending posts in responses. xAI does not publish technical details of how the X data connection works.
In xAI's launch figures, Grok 4 scored 15.9% on ARC-AGI-2, and Grok 4 Heavy scored 50.7% on the text-only subset of Humanity's Last Exam (HLE) and 61.9% on USAMO 2025. TechCrunch reported launch-livestream HLE scores of 25.4% for Grok 4 without tools and 44.4% for Grok 4 Heavy with tools.
At launch in July 2025, xAI said an AI coding model would follow in August, a multimodal agent in September, and a video-generation model in October 2025.
At launch, xAI's figures put Grok 4 ahead of OpenAI's o3 (high) and Gemini 2.5 Pro on HLE without tools, and Grok 4 Heavy at the top of the HLE-with-tools category. These are vendor-reported numbers from July 2025, and newer models from every major lab have since been released.
| Benchmark (xAI-reported, July 2025) | Grok 4 | Grok 4 Heavy | OpenAI o3 (high) | Gemini 2.5 Pro |
|---|---|---|---|---|
| HLE (without tools) | 25.4% | - | 21% | 21.6% |
| HLE (with tools) | - | 44.4% | - | 26.9% |
| HLE (text-only subset) | - | 50.7% | - | - |
| ARC-AGI-2 | 15.9% | - | - | - |
| USAMO 2025 | - | 61.9% | - | - |
Grok 4 Heavy's 61.9% on USAMO 2025 was the top score xAI reported at launch. Competitor figures in the HLE rows are as reported by TechCrunch from xAI's launch presentation. Newer frontier models have been released since July 2025.
At launch in July 2025, xAI introduced SuperGrok Heavy at $300/month for access to Grok 4 Heavy, while standard Grok 4 came with SuperGrok and X Premium+. X Premium+ was a separate way to get Grok 4, not a requirement for SuperGrok.
Free Tier
Model: limited access to Grok
Cost: $0/month
Features: Basic functionality with lower usage limits
SuperGrok
Model: Grok 4 standard (at launch)
Cost: see grok.com/plans for the current price
Features: Full Grok 4 access, real-time search, higher usage limits
SuperGrok Heavy
Model: Grok 4 Heavy multi-agent (at launch)
Cost: $300/month (at launch, July 2025)
Features: Early preview of Grok 4 Heavy, early access to new features, highest usage limits
Grok 4 was also included with X Premium+ at launch. Plan names, prices and included models change often; as of September 2026, check grok.com/plans ↗ for current prices before subscribing.
OpenRouter provides pay-per-use API access without monthly subscriptions. Users pay only for actual token usage. As of September 2026, OpenRouter lists current xAI models such as x-ai/grok-4.7 rather than the original x-ai/grok-4.
Access Grok through a SuperGrok subscription on grok.com and the Grok apps, through X Premium tiers, or through the xAI API and OpenRouter on pay-per-use pricing. As of September 2026, the API serves newer Grok 4.x models rather than the original Grok 4.
Sign in at grok.com or in the Grok mobile app and choose a plan, or use Grok inside X with an eligible X Premium subscription. SuperGrok and SuperGrok Heavy are purchased through Grok itself. Grok is available on the web, in the Grok apps, and within X.
Create an account at OpenRouter.ai ↗ without subscription requirements. Add credits to the account for pay-as-you-go usage. Access current Grok models via the API using a model ID such as x-ai/grok-4.7.
Users get better results by providing specific, detailed prompts. Ask about current events to use real-time search. Use the Heavy tier for complex, multi-step problems. Use X integration for social media insights and trending analysis.
Grok 4 is suited to tasks that benefit from real-time X and web data, such as market sentiment summaries, research on recent developments, content based on trending discussions, and multi-step problem-solving with the Heavy variant.
Market analysis queries can summarize current sentiment on X about specific stocks alongside recent news. Research queries can compare recently posted papers with established work, since Grok can search for current sources.
Content creation can draw on trending discussions, for example drafting threads about current AI news. Grok can incorporate trending topics and hashtags into content suggestions. Grok 4 Heavy can be applied to complex planning problems, such as transport or infrastructure design questions.
Multi-agent collaboration suits multi-step problems like business strategy that combines market sentiment, competitor analysis, and consumer trends from X.
On July 8, 2025, the day before Grok 4 launched, the @grok account on X posted antisemitic content, including calling itself "MechaHitler", NPR reported ↗. xAI removed the posts and later apologized.
The posts followed a system prompt update telling the bot not to shy away from politically incorrect claims. xAI removed the posts, said it had taken action to ban hate speech before Grok posts on X, and later attributed the behavior to an update to the @grok bot's code path rather than the underlying model. The incident happened on the X bot, the day before Grok 4's July 9 launch.
Privacy concerns center on X sharing public user data with xAI for model training. Critics raise questions about data usage transparency and model training practices.
At launch, TechCrunch noted that the $300/month SuperGrok Heavy plan was the most expensive subscription among major AI providers. The free tier offers fewer features than paid plans.
At the July 2025 launch, xAI announced a coding model for August, a multimodal agent for September, and a video-generation model for October 2025. As of September 2026, xAI's API docs list Grok 4.3 through Grok 4.7 and do not list a Grok 5.
The planned coding model was announced as a specialized model for programming work. The multimodal agent was announced to extend Grok beyond text.
The video-generation model was announced for October 2025. It would compete with Runway and other video generation platforms.
Grok 5 had not appeared in xAI's API model list as of September 2026. The release timeline since launch has been rapid, with Grok 4.20, 4.3, 4.5, 4.6 and 4.7 listed in xAI's docs.
Choose Grok if you need real-time social media insights and the price of a paid plan fits your budget. Consider alternatives if you need strict content moderation or have budget constraints.
Grok suits users who need real-time data and social media insights for business decisions. The Heavy tier targets complex problems that benefit from multiple analytical perspectives. Users working within the X ecosystem benefit from native integration and current events understanding.
Consider alternatives if you require strict content moderation, operate with limited budgets, prefer established AI ecosystems like OpenAI or Anthropic, or want to avoid the controversy risks described above.
The Heavy tier targets power users who need the most reasoning compute. SuperGrok is the middle ground between free AI tools and the Heavy tier. OpenRouter offers pay-as-you-go API access to current Grok models before any subscription commitment.
Q: What makes Grok 4 Heavy different from standard Grok 4?
A: Grok 4 Heavy runs multiple agents in parallel on the same problem and compares their answers. xAI reported 44.4% on HLE with tools for Grok 4 Heavy versus 25.4% without tools for standard Grok 4 (July 2025 figures).
Q: Can I access Grok 4 without an X subscription?
A: Yes. SuperGrok is sold directly through Grok, and the xAI API and OpenRouter offer pay-per-use access. As of September 2026, the API offers newer Grok 4.x models rather than the original Grok 4.
Q: When will Grok 4 support images and video?
A: At launch in July 2025, xAI announced a multimodal agent for September 2025 and a video-generation model for October 2025. Check xAI's current docs for what is available today.
Q: How does Grok 4's real-time X integration work?
A: Grok 4 has native tool use with real-time search, which lets it pull current posts and web results into its answers. xAI does not publish lower-level details of the connection.
Q: Is Grok 4 worth the $300/month Heavy pricing?
A: It depends on workload. xAI reported 61.9% on USAMO 2025 for Grok 4 Heavy at launch, but the Heavy tier only pays off for users who regularly need the most compute; occasional users can start on the free tier or SuperGrok.
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