# Mellum2-12B-A2.5B-Thinking vs Sakana Fugu

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

- Canonical page: https://benchlm.ai/compare/mellum2-12b-a2-5b-thinking-vs-sakana-fugu
- Last updated: September 27, 2026

- Shared sourced benchmarks: 3
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.7

## Quick Verdict

Evidence is too thin for a benchmark verdict: Mellum2-12B-A2.5B-Thinking and Sakana Fugu share only 3 sourced benchmark rows.

## Summary

- Only 3 shared sourced benchmark rows are available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Sakana Fugu has the larger published context window at 1M.

## Model Snapshot

| Property | Mellum2-12B-A2.5B-Thinking | Sakana Fugu |
|----------|----------|----------|
| Creator | JetBrains | Sakana AI |
| Type | Open Weight | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 128K | 1M |
| Independent public score (not head-to-head) | null | null |
| Benchmarks Covered | 6 | 11 |
| Pricing (input/output) | N/A | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon
- Sakana Fugu public-lane score: Coming soon

| Benchmark | Mellum2-12B-A2.5B-Thinking | Sakana Fugu | Winner |
|-----------|-----------|-----------|--------|
| BFCL v4 | 45.6% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 80.2% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon
- Sakana Fugu public-lane score: Coming soon

| Benchmark | Mellum2-12B-A2.5B-Thinking | Sakana Fugu | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench v6 | 69.9% | 92.9% | Sakana Fugu |
| SWE-bench Pro | Coming soon | 59% | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 80.2% | Coming soon |
| LiveCodeBench Pro | Coming soon | 87.8% | Coming soon |
| SciCode | Coming soon | 60.1% | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon
- Sakana Fugu public-lane score: 70.6 (Unranked · 1 rankable row)

| Benchmark | Mellum2-12B-A2.5B-Thinking | Sakana Fugu | Winner |
|-----------|-----------|-----------|--------|
| MRCRv2 | Coming soon | 86.6% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon
- Sakana Fugu public-lane score: 68.6 (Unranked · 1 rankable row)

| Benchmark | Mellum2-12B-A2.5B-Thinking | Sakana Fugu | Winner |
|-----------|-----------|-----------|--------|
| CharXiv | Coming soon | 85.1% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon
- Sakana Fugu public-lane score: Coming soon

| Benchmark | Mellum2-12B-A2.5B-Thinking | Sakana Fugu | Winner |
|-----------|-----------|-----------|--------|
| MMLU-Redux | 86.2% | Coming soon | Coming soon |
| GPQA | 57.6% | 95.5% | Sakana Fugu |
| GPQA-D | 57.6% | 95.5% | Sakana Fugu |
| HLE w/o tools | Coming soon | 47.2% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon
- Sakana Fugu public-lane score: Coming soon

| Benchmark | Mellum2-12B-A2.5B-Thinking | Sakana Fugu | Winner |
|-----------|-----------|-----------|--------|
| IFEval | 76.5% | Coming soon | Coming soon |

## FAQ

### Is there enough evidence to pick between Mellum2-12B-A2.5B-Thinking and Sakana Fugu?

Not yet. The models share only 3 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

- [Mellum2-12B-A2.5B-Thinking vs Mellum2-12B-A2.5B-Instruct](/compare/mellum2-12b-a2-5b-instruct-vs-mellum2-12b-a2-5b-thinking)
- [Sakana Fugu vs Mellum2-12B-A2.5B-Instruct](/compare/mellum2-12b-a2-5b-instruct-vs-sakana-fugu)
- [Mellum2-12B-A2.5B-Thinking vs Sakana Fugu-Ultra](/compare/mellum2-12b-a2-5b-thinking-vs-sakana-fugu-ultra)
- [Sakana Fugu vs Sakana Fugu-Ultra](/compare/sakana-fugu-vs-sakana-fugu-ultra)

## Explore More

- [Mellum2-12B-A2.5B-Thinking profile](/models/mellum2-12b-a2-5b-thinking)
- [Sakana Fugu profile](/models/sakana-fugu)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)