# Gemma 4 31B vs Mellum2-12B-A2.5B-Thinking

> Side-by-side benchmark comparison for Gemma 4 31B and Mellum2-12B-A2.5B-Thinking across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/gemma-4-31b-vs-mellum2-12b-a2-5b-thinking
- Last updated: September 4, 2026

- Shared sourced benchmarks: 1
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: Gemma 4 31B and Mellum2-12B-A2.5B-Thinking share only 1 sourced benchmark row.

## Summary

- Only 1 shared sourced benchmark row is available. That is not enough for a broad capability verdict, so this mirror does not name an overall winner.
- Gemma 4 31B has the larger published context window at 256K.

## Model Snapshot

| Property | Gemma 4 31B | Mellum2-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | Google | JetBrains |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 256K | 128K |
| Independent public score (not head-to-head) | 58.69 | null |
| Benchmarks Covered | 8 | 6 |
| Pricing (input/output) | $0.00 / $0.00 | N/A |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 27.6 (Supported · #140/151)
- Mellum2-12B-A2.5B-Thinking public-lane score: 48.3 (Estimated · #76/151)

| Benchmark | Gemma 4 31B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| Gert Labs | 35.26% | Coming soon | Coming soon |
| BFCL v4 | Coming soon | 45.6% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 43.5 (Supported · #123/183)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Gemma 4 31B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| SWE-Rebench | 41.6% | Coming soon | Coming soon |
| React Native Evals | 75.2% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 69.9% | Coming soon |

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 58.4 (#30/48)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Gemma 4 31B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 76.9% | Coming soon | Coming soon |

### Reasoning

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 70.1 (Unranked · 2 rankable rows)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 47.9 (Supported · #104/181)
- Mellum2-12B-A2.5B-Thinking public-lane score: 48.8 (Estimated · #96/181)

| Benchmark | Gemma 4 31B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 84.3% | 57.6% | Gemma 4 31B |
| MMLU-Pro | 85.2% | Coming soon | Coming soon |
| HLE | 26.5% | Coming soon | Coming soon |
| HLE w/o tools | 19.5% | Coming soon | Coming soon |
| MMLU-Redux | Coming soon | 86.2% | Coming soon |
| GPQA-D | Coming soon | 57.6% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Gemma 4 31B public-lane score: 92.6 (#12/120)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Gemma 4 31B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 76.5% | Coming soon |

## FAQ

### Is there enough evidence to pick between Gemma 4 31B and Mellum2-12B-A2.5B-Thinking?

Not yet. The models share only 1 sourced benchmark row, 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

- [Gemma 4 31B vs Gemma 4 26B A4B](/compare/gemma-4-26b-a4b-vs-gemma-4-31b)
- [Mellum2-12B-A2.5B-Thinking vs Gemma 4 26B A4B](/compare/gemma-4-26b-a4b-vs-mellum2-12b-a2-5b-thinking)
- [Gemma 4 31B vs Gemma 4 12B](/compare/gemma-4-12b-vs-gemma-4-31b)
- [Mellum2-12B-A2.5B-Thinking vs Gemma 4 12B](/compare/gemma-4-12b-vs-mellum2-12b-a2-5b-thinking)

## Explore More

- [Gemma 4 31B profile](/models/gemma-4-31b)
- [Mellum2-12B-A2.5B-Thinking profile](/models/mellum2-12b-a2-5b-thinking)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)