Model Comparison

Grok-4 Heavy vs LongCat-Flash-ThinkingWhich is better in 2026?

Grok-4 Heavy shows notably better performance in the majority of benchmarks.

Verdict: Grok-4 Heavy vs LongCat-Flash-Thinking — which is better?

Grok-4 Heavy (by xAI) and LongCat-Flash-Thinking (by Meituan) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Grok-4 Heavy outperforms in 2 benchmarks (AIME 2025, GPQA), while LongCat-Flash-Thinking is better at 0 benchmarks. Grok-4 Heavy shows notably better performance in the majority of benchmarks.

Choose Grok-4 Heavy if…

  • you want the strongest raw capability — it leads on 2 of 3 shared benchmarks

Choose LongCat-Flash-Thinking if…

  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

Grok-4 Heavy outperforms in 2 benchmarks (AIME 2025, GPQA), while LongCat-Flash-Thinking is better at 0 benchmarks.

Grok-4 Heavy shows notably better performance in the majority of benchmarks.

Thu Jul 30 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only LongCat-Flash-Thinking specifies input context (128,000 tokens). Only LongCat-Flash-Thinking specifies output context (128,000 tokens).

xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Meituan
LongCat-Flash-Thinking
Input128,000 tokens
Output128,000 tokens
Thu Jul 30 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Grok-4 Heavy supports multimodal inputs, whereas LongCat-Flash-Thinking does not.

Grok-4 Heavy can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok-4 Heavy

Text
Images
Audio
Video

LongCat-Flash-Thinking

Text
Images
Audio
Video

License

Usage and distribution terms

Grok-4 Heavy is licensed under a proprietary license, while LongCat-Flash-Thinking uses MIT.

License differences may affect how you can use these models in commercial or open-source projects.

Grok-4 Heavy

Proprietary

Closed source

LongCat-Flash-Thinking

MIT

Open weights

Release Timeline

When each model was launched

LongCat-Flash-Thinking was released on 2025-09-22, while Grok-4 Heavy's release date is not specified.

We can confirm LongCat-Flash-Thinking's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Grok-4 Heavy

—

LongCat-Flash-Thinking

Sep 22, 2025

10 months ago

Knowledge Cutoff

When training data ends

Grok-4 Heavy has a documented knowledge cutoff of 2024-12-31, while LongCat-Flash-Thinking's cutoff date is not specified.

We can confirm Grok-4 Heavy's training data extends to 2024-12-31, but cannot make a direct comparison without LongCat-Flash-Thinking's cutoff date.

Grok-4 Heavy

Dec 2024

LongCat-Flash-Thinking

—

Outputs Comparison

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Key Takeaways

xAI
Supports multimodal inputs
Higher AIME 2025 score (100.0% vs 90.6%)
Higher GPQA score (88.4% vs 81.5%)
Meituan
Larger context window (128,000 tokens)
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Grok-4 Heavy and LongCat-Flash-Thinking side-by-side, then vote on the output you prefer.

Grok-4 Heavy
✓ Preferred
LongCat-Flash-Thinking
Open in Playground
AI Model Comparison Table
Feature
xAI
Grok-4 Heavy
Meituan
LongCat-Flash-Thinking

FAQ

Common questions about Grok-4 Heavy vs LongCat-Flash-Thinking.

Which is better, Grok-4 Heavy or LongCat-Flash-Thinking?

Grok-4 Heavy shows notably better performance in the majority of benchmarks. Grok-4 Heavy is made by xAI and LongCat-Flash-Thinking is made by Meituan. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok-4 Heavy compare to LongCat-Flash-Thinking in benchmarks?

Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%. LongCat-Flash-Thinking scores MATH-500: 99.2%, ZebraLogic: 95.5%, AIME 2024: 93.3%, AIME 2025: 90.6%, MMLU-Redux: 89.3%.

What are the context window sizes for Grok-4 Heavy and LongCat-Flash-Thinking?

Grok-4 Heavy supports an unknown number of tokens and LongCat-Flash-Thinking supports 128K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok-4 Heavy and LongCat-Flash-Thinking?

Key differences include multimodal support (yes vs no), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-4 Heavy and LongCat-Flash-Thinking?

Grok-4 Heavy is developed by xAI and LongCat-Flash-Thinking is developed by Meituan.

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