# MAI-Thinking-1 vs Mellum2-12B-A2.5B-Thinking

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

- Canonical page: https://benchlm.ai/compare/mai-thinking-1-vs-mellum2-12b-a2-5b-thinking
- Last updated: September 4, 2026

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

## Quick Verdict

Evidence is too thin for a benchmark verdict: MAI-Thinking-1 and Mellum2-12B-A2.5B-Thinking 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.
- MAI-Thinking-1 has the larger published context window at 256K.

## Model Snapshot

| Property | MAI-Thinking-1 | Mellum2-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | Microsoft | JetBrains |
| Type | Proprietary | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 256K | 128K |
| Independent public score (not head-to-head) | 52.27 | null |
| Benchmarks Covered | 14 | 6 |
| Pricing (input/output) | N/A | N/A |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- MAI-Thinking-1 public-lane score: 51.7 (Estimated · #53/151)
- Mellum2-12B-A2.5B-Thinking public-lane score: 48.3 (Estimated · #76/151)

| Benchmark | MAI-Thinking-1 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 46% | Coming soon | Coming soon |
| BFCL v4 | Coming soon | 45.6% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- MAI-Thinking-1 public-lane score: 51.8 (Estimated · #60/183)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | MAI-Thinking-1 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| LiveCodeBench v6 | 87.7% | 69.9% | MAI-Thinking-1 |
| SWE-bench Verified | 73.5% | Coming soon | Coming soon |
| SWE-bench Pro | 52.8% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 46.0% | Coming soon | Coming soon |

### Reasoning

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

| Benchmark | MAI-Thinking-1 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| Graphwalks BFS 128K | 90% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- MAI-Thinking-1 public-lane score: 53.3 (Estimated · #68/181)
- Mellum2-12B-A2.5B-Thinking public-lane score: 48.8 (Estimated · #96/181)

| Benchmark | MAI-Thinking-1 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 84.2% | 57.6% | MAI-Thinking-1 |
| GPQA-D | 84.2% | 57.6% | MAI-Thinking-1 |
| MMLU-Pro | 85% | Coming soon | Coming soon |
| SimpleQA | 31% | Coming soon | Coming soon |
| MMLU-Redux | Coming soon | 86.2% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- MAI-Thinking-1 public-lane score: 94.7 (#1/120)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | MAI-Thinking-1 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFBench | 85% | Coming soon | Coming soon |
| IFEval | Coming soon | 76.5% | Coming soon |

### Mathematics

- Winner: Insufficient shared evidence
- MAI-Thinking-1 public-lane score: 73.4 (Unranked · 3 rankable rows)
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | MAI-Thinking-1 | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| AIME 2025 | 97% | Coming soon | Coming soon |
| AIME26 | 94.5% | Coming soon | Coming soon |
| HMMT Feb 2026 | 84.9% | Coming soon | Coming soon |

## FAQ

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

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

- [MAI-Thinking-1 vs Mellum2-12B-A2.5B-Instruct](/compare/mai-thinking-1-vs-mellum2-12b-a2-5b-instruct)
- [Mellum2-12B-A2.5B-Thinking vs Mellum2-12B-A2.5B-Instruct](/compare/mellum2-12b-a2-5b-instruct-vs-mellum2-12b-a2-5b-thinking)
- [MAI-Thinking-1 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mai-thinking-1)
- [Mellum2-12B-A2.5B-Thinking vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-mellum2-12b-a2-5b-thinking)

## Explore More

- [MAI-Thinking-1 profile](/models/mai-thinking-1)
- [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)