# Inkling-Small vs Mellum2.1-12B-A2.5B-Thinking

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

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

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Pick Inkling-Small if you want the stronger benchmark profile. Mellum2.1-12B-A2.5B-Thinking only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Inkling-Small leads overall 54.49 to 37.
- The biggest single benchmark swing is Terminal-Bench 2.1 in Agentic, with scores of 64.7% and 17.4%.
- Mellum2.1-12B-A2.5B-Thinking is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Inkling-Small also has the larger context window at 1M.

## Model Snapshot

| Property | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | Thinking Machines Lab | JetBrains |
| Type | Open Weight | Open Weight |
| Reasoning | Hybrid | Reasoning |
| Context | 1M | 128K |
| Overall Score | 54.49 | null |
| Benchmarks Covered | 26 | 7 |
| Pricing (input/output) | $0.58 / $1.44 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Not comparable
- Inkling-Small public-lane score: 35.8 (Supported · #72/122)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.1 | 64.7% | 17.4% | Inkling-Small |
| BrowseComp | 77.4% | Coming soon | Coming soon |
| MCP Atlas | 79.6% | Coming soon | Coming soon |
| Toolathlon-Verified | 54.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 55.1% | Coming soon | Coming soon |

### Coding

- Winner: Not comparable
- Inkling-Small public-lane score: 38.7 (Supported · #66/146)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 80.2% | 47% | Inkling-Small |
| SWE-bench Pro | 55.9% | 28% | Inkling-Small |
| Terminal-Bench 2.1 | 64.7% | Coming soon | Coming soon |
| SciCode | 48.7% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 85.9% | Coming soon | Coming soon |
| SWE-bench (Vals) | 82.2% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 82.0% | Coming soon |

### Reasoning

- Winner: Not comparable
- Inkling-Small public-lane score: 51.4 (Unranked · 4 rankable rows)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 40.1% | Coming soon | Coming soon |
| CritPt | 8.3% | Coming soon | Coming soon |
| ARC-AGI-1 | 84.00% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Not comparable
- Inkling-Small public-lane score: 49.8 (#39/49)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | 74% | Coming soon | Coming soon |
| CharXiv | 81.3% | Coming soon | Coming soon |
| CharXiv w/o tools | 77.4% | Coming soon | Coming soon |

### Knowledge

- Winner: Not comparable
- Inkling-Small public-lane score: 53.7 (Supported · #55/174)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 89.5% | Coming soon | Coming soon |
| GPQA-D | 89.5% | 64.6% | Inkling-Small |
| HLE | 47.8% | Coming soon | Coming soon |
| HLE w/o tools | 31.6% | Coming soon | Coming soon |
| GPQA Diamond (Vals) | 83.6% | Coming soon | Coming soon |
| MMLU-Pro (Vals) | 85.6% | Coming soon | Coming soon |
| MMLU-Redux | Coming soon | 87.8% | Coming soon |

### Instruction Following

- Winner: Not comparable
- Inkling-Small public-lane score: 88.5 (#23/125)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFBench | 82.2% | Coming soon | Coming soon |
| IFEval | Coming soon | 90.6% | Coming soon |

### Mathematics

- Winner: Not comparable
- Inkling-Small public-lane score: 76.5 (Unranked · 2 rankable rows)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Inkling-Small | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| AIME26 | 95.5% | Coming soon | Coming soon |
| HMMT Feb 2026 | 90.2% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Inkling-Small or Mellum2.1-12B-A2.5B-Thinking?

Inkling-Small is ahead overall on BenchLM right now.

### How many benchmarks does Inkling-Small cover on BenchLM?

Inkling-Small currently has 26 sourced benchmark scores on BenchLM.

### How many benchmarks does Mellum2.1-12B-A2.5B-Thinking cover on BenchLM?

Mellum2.1-12B-A2.5B-Thinking currently has 7 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Inkling-Small vs Inkling](/compare/inkling-vs-inkling-small)
- [Mellum2.1-12B-A2.5B-Thinking vs Inkling](/compare/inkling-vs-mellum2-1-12b-a2-5b-thinking)
- [Inkling-Small vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-inkling-small)
- [Mellum2.1-12B-A2.5B-Thinking vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-mellum2-1-12b-a2-5b-thinking)

## Explore More

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