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Grok-1.5 vs Muse Spark Open

Muse Spark Open leads the LLM Stats Score 44.9 to -3.0.

xAI · Meta · Updated for 2026

Which is better?

Muse Spark Open leads the overall LLM Stats Score 44.9 to -3.0, ranking #43 overall.

In the 1 individual benchmarks reported for both models, Muse Spark Open wins 1; this is a narrower head-to-head signal than the composite indexes.

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

Choose Grok-1.5

  • you are already invested in the xAI ecosystem

Choose Muse Spark Open

  • overall performance matters — it scores 44.9 and ranks #43 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results
  • you want the most recent training data — it shipped Oct 2026
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Grok-1.5
xAI
Muse Spark Open
Meta
Core performance indexes
LLM Stats Score
-3.0
#364
44.9
#43
Reasoning
-2.5
#355
45.2
#39
Coding
-1.0
#269
33.0
#42
Cost, coverage & limits
Benchmark wins
0 of 1
1 of 1
Input price
— / M
$1.25 / M
Output price
— / M
$4.25 / M
Context window
—
1,048,576

Capability indexes

Additional strengths measured across groups of related public benchmarks

3 shared
Index
Grok-1.5
Muse Spark Open
Math
4.9#289
31.6#69
Vision
-5.3#222
31.2#34
Multimodal
-2.7#180
33.1#20
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

9 reported for Grok-1.5 · 17 for Muse Spark Open

1 shared

Grok-1.5 outperforms in 0 benchmarks, while Muse Spark Open is better at 1 benchmark (GPQA).

Muse Spark Open significantly outperforms across most benchmarks.

Wed Oct 21 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Muse Spark Open specifies input context (1,048,576 tokens). Only Muse Spark Open specifies output context (1,048,576 tokens).

xAI
Grok-1.5
Input- tokens
Output- tokens
Meta
Muse Spark Open
Input1,048,576 tokens
Output1,048,576 tokens
Wed Oct 21 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Muse Spark Open supports multimodal inputs, whereas Grok-1.5 does not.

Muse Spark Open can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok-1.5

Text
Images
Audio
Video

Muse Spark Open

Text
Images
Audio
Video

License

Usage and distribution terms

Grok-1.5 is licensed under a proprietary license, while Muse Spark Open uses Muse Model License.

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

Grok-1.5

Proprietary

Closed source

Muse Spark Open

Muse Model License

Open weights

Release Timeline

When each model was launched

Grok-1.5 was released on 2024-03-28, while Muse Spark Open was released on 2026-10-15.

Muse Spark Open is 31 months newer than Grok-1.5.

Grok-1.5

Mar 28, 2024

2.6 years ago

Muse Spark Open

Oct 15, 2026

2 days ago

2.6yr newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Grok-1.5 and Muse Spark Open side-by-side, then vote on the output you prefer.

Grok-1.5
✓ Preferred
Muse Spark Open
Open in Playground

FAQ

Common questions about Grok-1.5 vs Muse Spark Open.

Which is better, Grok-1.5 or Muse Spark Open?

Muse Spark Open leads the LLM Stats Score 44.9 to -3.0. Grok-1.5 is made by xAI and Muse Spark Open 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-1.5 compare to Muse Spark Open in benchmarks?

Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%. Muse Spark Open scores MCP Atlas: 89.2%, GPQA: 89.0%, OSWorld-Verified: 80.4%, BabyVision: 80.2%, Terminal-Bench 2.1: 76.4%.

What are the context window sizes for Grok-1.5 and Muse Spark Open?

Grok-1.5 supports an unknown number of tokens and Muse Spark Open 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-1.5 and Muse Spark Open?

Key differences include LLM Stats Score (-3.0 vs 44.9), multimodal support (no vs yes), licensing (Proprietary vs Muse Model License). See the full comparison above for benchmark-by-benchmark results.

Who makes Grok-1.5 and Muse Spark Open?

Grok-1.5 is developed by xAI and Muse Spark Open is developed by Meta.

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