The AI arena is free today

Open Superagent

Muse Spark Open vs Solar Pro 4

Muse Spark Open leads the LLM Stats Score 44.9 to 35.0. Solar Pro 4 is 3.8x cheaper per token.

Meta · Upstage · Updated for 2026

Which is better?

Muse Spark Open leads the overall LLM Stats Score 44.9 to 35.0, ranking #43 overall.

The models split the 2 individual benchmarks reported for both models evenly.

On price, Solar Pro 4 is roughly 3.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Muse Spark Open also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.

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

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 process long inputs — it offers a 1,048,576 token context window
  • you want the most recent training data — it shipped Oct 2026
  • you need open weights you can self-host or fine-tune

Choose Solar Pro 4

  • cost matters — it's about 3.8x cheaper per token

At a glance

The differences that matter most.

Muse Spark Open
Meta
Solar Pro 4
Upstage
Core performance indexes
LLM Stats Score
44.9
#43
35.0
#107
Reasoning
45.2
#39
34.7
#102
Coding
33.0
#42
20.6
#112
Agents
30.6
#43
12.0
#128
Cost, coverage & limits
Benchmark wins
1 of 2
1 of 2
Input price
$1.25 / M
$0.30 / M
Output price
$4.25 / M
$1.20 / M
Context window
1,048,576
524,288

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Muse Spark Open
Solar Pro 4
Math
31.6#69
32.4#63
Tool use
23.3#44
9.6#149
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

17 reported for Muse Spark Open · 9 for Solar Pro 4

2 shared

Muse Spark Open outperforms in 1 benchmarks (Terminal-Bench 2.1), while Solar Pro 4 is better at 0 benchmarks.

Muse Spark Open has a slight edge in benchmark performance.

Mon Oct 19 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

Solar Pro 4 costs less

For input processing, Muse Spark Open ($1.25/1M tokens) is 4.2x more expensive than Solar Pro 4 ($0.30/1M tokens).

For output processing, Muse Spark Open ($4.25/1M tokens) is 3.5x more expensive than Solar Pro 4 ($1.20/1M tokens).

In conclusion, Muse Spark Open is more expensive than Solar Pro 4.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Mon Oct 19 2026 • llm-stats.com
Meta
Muse Spark Open
Input tokens$1.25
Output tokens$4.25
Best providerTogether
Upstage
Solar Pro 4
Input tokens$0.30
Output tokens$1.20
Best providerUnknown Organization
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Muse Spark Open accepts 1,048,576 input tokens compared to Solar Pro 4's 524,288 tokens. Muse Spark Open can generate longer responses up to 1,048,576 tokens, while Solar Pro 4 is limited to 131,072 tokens.

Meta
Muse Spark Open
Input1,048,576 tokens
Output1,048,576 tokens
Upstage
Solar Pro 4
Input524,288 tokens
Output131,072 tokens
Mon Oct 19 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Muse Spark Open supports multimodal inputs, whereas Solar Pro 4 does not.

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

Muse Spark Open

Text
Images
Audio
Video

Solar Pro 4

Text
Images
Audio
Video

License

Usage and distribution terms

Muse Spark Open is licensed under Muse Model License, while Solar Pro 4 uses a proprietary license.

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

Muse Spark Open

Muse Model License

Open weights

Solar Pro 4

Proprietary

Closed source

Release Timeline

When each model was launched

Muse Spark Open was released on 2026-10-15, while Solar Pro 4 was released on 2026-08-06.

Muse Spark Open is 2 months newer than Solar Pro 4.

Muse Spark Open

Oct 15, 2026

4 days ago

2mo newer
Solar Pro 4

Aug 6, 2026

2 months ago

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

Provider Availability

Muse Spark Open is available from Together. Solar Pro 4 is available from Upstage.

Muse Spark Open

together logo
Together
Input Price:Input: $1.25/1MOutput Price:Output: $4.25/1M

Solar Pro 4

upstage logo
Unknown Organization
Input Price:Input: $0.30/1MOutput Price:Output: $1.20/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Muse Spark Open and Solar Pro 4 side-by-side, then vote on the output you prefer.

Muse Spark Open
✓ Preferred
Solar Pro 4
Open in Playground

FAQ

Common questions about Muse Spark Open vs Solar Pro 4.

Which is better, Muse Spark Open or Solar Pro 4?

Muse Spark Open leads the LLM Stats Score 44.9 to 35.0. Muse Spark Open is made by Meta and Solar Pro 4 is made by Upstage. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Muse Spark Open compare to Solar Pro 4 in benchmarks?

Muse Spark Open scores MCP Atlas: 89.2%, GPQA: 89.0%, OSWorld-Verified: 80.4%, BabyVision: 80.2%, Terminal-Bench 2.1: 76.4%. Solar Pro 4 scores AIME 2026: 95.3%, GPQA: 89.0%, LiveCodeBench: 87.8%, MMLU-Pro: 86.3%, AA-LCR: 71.0%.

Is Muse Spark Open cheaper than Solar Pro 4?

Solar Pro 4 is 4.2x cheaper for input tokens. Muse Spark Open costs $1.25/M input and $4.25/M output via together. Solar Pro 4 costs $0.30/M input and $1.20/M output via upstage.

What are the context window sizes for Muse Spark Open and Solar Pro 4?

Muse Spark Open supports 1.0M tokens and Solar Pro 4 supports 524K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Muse Spark Open and Solar Pro 4?

Key differences include LLM Stats Score (44.9 vs 35.0), context window (1.0M vs 524K), input pricing ($1.25 vs $0.30/M), multimodal support (yes vs no), licensing (Muse Model License vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes Muse Spark Open and Solar Pro 4?

Muse Spark Open is developed by Meta and Solar Pro 4 is developed by Upstage.

Related comparisons