# Mellum2.1-12B-A2.5B-Thinking vs Muse Spark 1.1

> Side-by-side benchmark comparison for Mellum2.1-12B-A2.5B-Thinking and Muse Spark 1.1 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/mellum2-1-12b-a2-5b-thinking-vs-muse-spark-1-1
- Last updated: October 8, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Evidence is too thin for a benchmark verdict: Mellum2.1-12B-A2.5B-Thinking and Muse Spark 1.1 share only 2 sourced benchmark rows.

## Summary

- Only 2 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Muse Spark 1.1 has the larger published context window at 1M.

## Model Snapshot

| Property | Mellum2.1-12B-A2.5B-Thinking | Muse Spark 1.1 |
|----------|----------|----------|
| Creator | JetBrains | Meta |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 128K | 1M |
| Independent public score (not head-to-head) | null | 65.83 |
| Benchmarks Covered | 7 | 26 |
| Pricing (input/output) | $0.00 / $0.00 | N/A |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Muse Spark 1.1 public-lane score: 57.1 (Supported · #32/122)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 17.4% | 80.0% | Muse Spark 1.1 |
| MCP Atlas | Coming soon | 88.1% | Coming soon |
| Toolathlon | Coming soon | 75.6% | Coming soon |
| OSWorld-Verified | Coming soon | 80.8% | Coming soon |
| WebArena-Verified | Coming soon | 69% | Coming soon |
| DeepSearchQA | Coming soon | 84.9% | Coming soon |
| CyberGym | Coming soon | 59.0% | Coming soon |
| Finance Agent v2 | Coming soon | 57.2% | Coming soon |
| deepSwe | Coming soon | 53.3% | Coming soon |
| OSWorld 2.0 | Coming soon | 14.2% | Coming soon |
| JobBench | Coming soon | 54.7% | Coming soon |
| Cybench | Coming soon | 92.9% | Coming soon |
| ExploitGym | Coming soon | 0.8% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 69.3% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Muse Spark 1.1 public-lane score: 53.7 (Supported · #35/146)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench v6 | 82.0% | Coming soon | Coming soon |
| SWE-bench Verified | 47% | Coming soon | Coming soon |
| SWE-bench Pro | 28% | 61.5% | Muse Spark 1.1 |
| Terminal-Bench 2.1 | Coming soon | 80.0% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 85.9% | Coming soon |
| SWE-bench (Vals) | Coming soon | 82.0% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Muse Spark 1.1 public-lane score: 75.7 (Unranked · 3 rankable rows)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| MRCR 1M | Coming soon | 54.1% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Muse Spark 1.1 public-lane score: 78.3 (Unranked · 2 rankable rows)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | Coming soon | 88.4% | Coming soon |
| BabyVision | Coming soon | 76.3% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Muse Spark 1.1 public-lane score: 66.6 (Supported · #21/174)

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Redux | 87.8% | Coming soon | Coming soon |
| GPQA-D | 64.6% | Coming soon | Coming soon |
| HLE | Coming soon | 62.1% | Coming soon |
| HLE w/o tools | Coming soon | 52.2% | Coming soon |
| HealthBench Professional | Coming soon | 59.3% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 91.2% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 88.7% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon
- Muse Spark 1.1 public-lane score: Coming soon

| Benchmark | Mellum2.1-12B-A2.5B-Thinking | Muse Spark 1.1 | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 90.6% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between Mellum2.1-12B-A2.5B-Thinking and Muse Spark 1.1?

Not yet. The models share only 2 sourced benchmark rows, so this mirror reports the available measurements and metadata without naming a broad winner.

### What can I compare safely on this page?

Published pricing, context windows, model type, and individual shared benchmark rows are directly comparable. Independent overall scores and non-overlapping benchmark coverage are labeled separately and should not be read as a controlled head-to-head result.

## Related Comparisons

- [Mellum2.1-12B-A2.5B-Thinking vs Muse Spark 1.2](/compare/mellum2-1-12b-a2-5b-thinking-vs-muse-spark-1-2)
- [Muse Spark 1.1 vs Muse Spark 1.2](/compare/muse-spark-1-1-vs-muse-spark-1-2)
- [Mellum2.1-12B-A2.5B-Thinking vs Muse Spark](/compare/mellum2-1-12b-a2-5b-thinking-vs-muse-spark)
- [Muse Spark 1.1 vs Muse Spark](/compare/muse-spark-vs-muse-spark-1-1)

## Explore More

- [Mellum2.1-12B-A2.5B-Thinking profile](/models/mellum2-1-12b-a2-5b-thinking)
- [Muse Spark 1.1 profile](/models/muse-spark-1-1)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)