The AI arena is free today

Open Superagent

Grok-4 Heavy vs Muse Spark 1.3

Muse Spark 1.3 leads the LLM Stats Score 55.3 to 40.9.

xAI · Meta · Updated for 2026

Which is better?

Muse Spark 1.3 leads the overall LLM Stats Score 55.3 to 40.9, ranking #5 overall.

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 Muse Spark 1.3

  • overall performance matters — it scores 55.3 and ranks #5 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes

At a glance

The differences that matter most.

Grok-4 Heavy
xAI
Muse Spark 1.3
Meta
Core performance indexes
LLM Stats Score
40.9
#50
55.3
#5
Reasoning
39.2
#53
52.8
#7
Coding
17.9
#108
41.7
#10
Cost, coverage & limits
Benchmark wins
—
—
Input price
— / M
$0.10 / M
Output price
— / M
$0.20 / M
Context window
—
1,048,576

Individual benchmarks

6 reported for Grok-4 Heavy · 11 for Muse Spark 1.3

No common benchmarks found

Grok-4 Heavy and Muse Spark 1.3don'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 Muse Spark 1.3 specifies input context (1,048,576 tokens). Only Muse Spark 1.3 specifies output context (943,718 tokens).

xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Meta
Muse Spark 1.3
Input1,048,576 tokens
Output943,718 tokens
Fri Sep 04 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Grok-4 Heavy and Muse Spark 1.3 support multimodal inputs.

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

Grok-4 Heavy

Text
Images
Audio
Video

Muse Spark 1.3

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Grok-4 Heavy

Proprietary

Closed source

Muse Spark 1.3

Proprietary

Closed source

Release Timeline

When each model was launched

Muse Spark 1.3 was released on 2026-09-02, while Grok-4 Heavy's release date is not specified.

We can confirm Muse Spark 1.3's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

Grok-4 Heavy

—

Muse Spark 1.3

Sep 2, 2026

2 days ago

Knowledge Cutoff

When training data ends

Grok-4 Heavy has a documented knowledge cutoff of 2024-12-31, while Muse Spark 1.3'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 Muse Spark 1.3's cutoff date.

Grok-4 Heavy

Dec 2024

Muse Spark 1.3

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Grok-4 Heavy and Muse Spark 1.3 side-by-side, then vote on the output you prefer.

Grok-4 Heavy
✓ Preferred
Muse Spark 1.3
Open in Playground

FAQ

Common questions about Grok-4 Heavy vs Muse Spark 1.3.

Which is better, Grok-4 Heavy or Muse Spark 1.3?

Muse Spark 1.3 leads the LLM Stats Score 55.3 to 40.9. Grok-4 Heavy is made by xAI and Muse Spark 1.3 is made by Meta. 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 Muse Spark 1.3 in benchmarks?

Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%. Muse Spark 1.3 scores MRCR v2 (8-needle): 98.5%, MRCR v2 (8-needle, 512K-1M): 98.1%, DeepSearchQA: 89.4%, Terminal-Bench 2.1: 88.8%, DeepSWE 1.1: 75.4%.

What are the context window sizes for Grok-4 Heavy and Muse Spark 1.3?

Grok-4 Heavy supports an unknown number of tokens and Muse Spark 1.3 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 Muse Spark 1.3?

Key differences include LLM Stats Score (40.9 vs 55.3). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-4 Heavy and Muse Spark 1.3?

Grok-4 Heavy is developed by xAI and Muse Spark 1.3 is developed by Meta.

Related comparisons