Grok 4 Heavy vs GPT-5: Benchmark Results, Key Differences & Market Impact (August 2025)

by

Here is a comprehensive overview of the current state of Grok 4 Heavy vs GPT-5 as of August 2025:

Grok 4 Heavy vs GPT-5

Grok 4 Heavy xAI

  • Claimed Superiority: Elon Musk asserts Grok 4 Heavy already outperforms GPT-5 in intelligence and practical benchmarks. This includes statements that Grok 4 was “smarter two weeks ago than GPT-5 is now

  • Release Date: July 9, 2025

  • Performance on Benchmarks:

    • ARC-AGI-2 (abstract reasoning): 15.9% (nearly double earlier leaders; most models fail to break 5%)

    • Humanity’s Last Exam: Grok 4 Heavy scores 44.4%, nearly double Gemini 2.5 Pro’s 25.4% and OpenAI’s o3 at 21%

    • AIME25 (math): 100% score, leading all competitors

    • Other victories include top scores on USAMO’25, GPQA Diamond, LiveCodeBench, and MMLU-Pro; Grok 4 scored 73 on Artificial Analysis’s Intelligence Index, ahead of Gemini 2.5 Pro and o3

  • Core Features:

    • Real-Time Info Access: Pulls live data from X (formerly Twitter), excels in fast-moving domains

    • Personality-Driven: Designed for witty, candid, and context-rich interaction. Less content moderation than competitors

    • Speed: Around 75 tokens/sec; noted as responsive but not the fastest

    • Subscription Levels: Grok 4 Heavy is premium (~$300/month for SuperGrok Heavy)

    • Controversies: Reports of less content moderation, some inappropriate content generated (xAI claims it’s being addressed)

  • Usage and AI Community Response:

    • Developers test Grok with entire codebases and report strong reasoning capabilities.

    • Scientists use it for complex, previously unsolved problems.

    • Users praise both its intelligence and its rebellious personality, but debate its open moderation

GPT-5 (OpenAI)

  • Release Date: August 7, 2025

  • Performance & Features:

    • Multimodal Capabilities: Handles text, code, images, and context switching in one conversation

    • Unified Model Router: Switches automatically between quick replies and deep analysis depending on complexity

    • Reasoning & Reliability: Substantially fewer hallucinations than GPT-4o—claims 45% reduction in factual errors, more honest about limitations

    • Coding & Work Tasks: Best-ever model for writing, coding, healthcare queries, and enterprise productivity; excels in long, complex agentic tasks

    • Safety: Employs “safe completions” that allow nuanced high-level safety responses rather than blanket denials, improved transparency about its limits

    • Personalization: Offers tone settings and more “human-like” interaction styles

    • Subscription & Access: Available to all ChatGPT users, with more powerful “GPT-5 Pro” available for enterprise and Plus users

    • Security: Tested against malware/fraud/scam generation and boasts strong AI safety profile

  • Market Impact:

    • Quickly rolled into products like Microsoft Copilot, GitHub, Azure AI, etc.

    • 700million+ users have access

  • Industry Reception:

    • Praised for reliability, efficiency, and improvements that matter in daily workflows, especially for coding, writing, and health questions

Comparison Table

Feature / Test Grok 4 Heavy GPT-5
Release Date July 9, 2025 Aug 7, 2025
ARC-AGI-2 (abstract reasoning) 15.9% Not publicly disclosed
Humanity’s Last Exam 44.4% Not publicly disclosed
AIME25 (math) 100% Not publicly disclosed
Live Data Access Yes (X/Twitter Limited (delayed data, batch updates)
Personality Style Witty, direct, rebellious Customizable tone/human-like
Multimodal/Unified Model Basic image support, text focus Advanced, seamless switching
Reasoning/Accuracy Leading most academic benchmarks Fewer hallucinations, high real-world reliability
Moderation/Safety Minimal filters, open responses “Safe completions,” robust safety
Coding/Programming Advanced but not main focus Market-leading; best-ever mode
Subscription/Access
User Base Growing, early enthusiasts 700M+ ChatGPT users, enterprise clients

Verdict

  • Grok 4 Heavy: Dominates in academic benchmarks, abstract reasoning, math, and live information tasks. Favored by users needing up-to-the-second info, personality-rich chat, and less filtered content. Its open approach is controversial but innovative.

  • GPT-5: Excels in multimodal reasoning, reliability, safety, coding, and broad enterprise usage—suited for users needing high accuracy, nuanced analysis, and a robust safety profile. The default for most professional and creative users

Which is better?
There is no universal winner. Grok 4 Heavy outpaces GPT-5 in specialized benchmarks and live info, while GPT-5 leads in broad usability, reliability, and safety. The rivalry is driving rapid advances and giving users real choice based on needs

No fully independent benchmarks have affirmed Musk’s claim yet, but the data suggests both models are at the frontier—with distinct strengths and innovations

Note: Both xAI and OpenAI continue to release updates, so expect fast ongoing improvements in capability, safety, and user experience