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Grok-4 Heavy vs MiMo-V2.6-Flash

Grok-4 Heavy and MiMo-V2.6-Flash are closely matched at 40.7 and 45.6 on the LLM Stats Score.

xAI · Xiaomi · Updated for 2026

Which is better?

Grok-4 Heavy and MiMo-V2.6-Flash are closely matched on the overall LLM Stats Score at 40.7 and 45.6.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Grok-4 Heavy

  • you are already invested in the xAI ecosystem

Choose MiMo-V2.6-Flash

  • your work emphasizes coding — it leads those capability indexes
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Grok-4 Heavy
xAI
MiMo-V2.6-Flash
Xiaomi
Core performance indexes
LLM Stats Score
40.7
#56
45.6
#29
Reasoning
39.0
#60
42.5
#45
Coding
17.7
#118
36.7
#21
Cost, coverage & limits
Benchmark wins
—
—
Input price
— / M
$0.14 / M
Output price
— / M
$0.28 / M
Context window
—
1,048,576

Individual benchmarks

6 reported for Grok-4 Heavy · 16 for MiMo-V2.6-Flash

No common benchmarks found

Grok-4 Heavy and MiMo-V2.6-Flashdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only MiMo-V2.6-Flash specifies input context (1,048,576 tokens).

xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Xiaomi
MiMo-V2.6-Flash
Input1,048,576 tokens
Output- tokens
Tue Sep 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Grok-4 Heavy and MiMo-V2.6-Flash support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Grok-4 Heavy

Text
Images
Audio
Video

MiMo-V2.6-Flash

Text
Images
Audio
Video

License

Usage and distribution terms

Grok-4 Heavy is licensed under a proprietary license, while MiMo-V2.6-Flash uses MIT.

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

Grok-4 Heavy

Proprietary

Closed source

MiMo-V2.6-Flash

MIT

Open weights

Release Timeline

When each model was launched

MiMo-V2.6-Flash was released on 2026-09-22, while Grok-4 Heavy's release date is not specified.

We can confirm MiMo-V2.6-Flash's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Grok-4 Heavy

—

MiMo-V2.6-Flash

Sep 22, 2026

-1 days ago

Knowledge Cutoff

When training data ends

Grok-4 Heavy has a documented knowledge cutoff of 2024-12-31, while MiMo-V2.6-Flash'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 MiMo-V2.6-Flash's cutoff date.

Grok-4 Heavy

Dec 2024

MiMo-V2.6-Flash

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Grok-4 Heavy and MiMo-V2.6-Flash side-by-side, then vote on the output you prefer.

Grok-4 Heavy
✓ Preferred
MiMo-V2.6-Flash
Open in Playground

FAQ

Common questions about Grok-4 Heavy vs MiMo-V2.6-Flash.

Which is better, Grok-4 Heavy or MiMo-V2.6-Flash?

Grok-4 Heavy and MiMo-V2.6-Flash are closely matched on the LLM Stats Score at 40.7 and 45.6. Grok-4 Heavy is made by xAI and MiMo-V2.6-Flash is made by Xiaomi. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Grok-4 Heavy compare to MiMo-V2.6-Flash in benchmarks?

Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%. MiMo-V2.6-Flash scores CyberGym: 95.1%, Terminal-Bench 2.1: 87.6%, OSWorld-Verified: 80.8%, MiMo Cyber Bench: 77.2%, Toolathlon-Verified: 73.6%.

What are the context window sizes for Grok-4 Heavy and MiMo-V2.6-Flash?

Grok-4 Heavy supports an unknown number of tokens and MiMo-V2.6-Flash supports 1.0M 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 MiMo-V2.6-Flash?

Key differences include LLM Stats Score (40.7 vs 45.6), licensing (Proprietary vs MIT). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-4 Heavy and MiMo-V2.6-Flash?

Grok-4 Heavy is developed by xAI and MiMo-V2.6-Flash is developed by Xiaomi.

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