# Hy3 Preview vs Mellum2.1-12B-A2.5B-Thinking

> Side-by-side benchmark comparison for Hy3 Preview and Mellum2.1-12B-A2.5B-Thinking across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/hy3-preview-vs-mellum2-1-12b-a2-5b-thinking
- 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: Hy3 Preview and Mellum2.1-12B-A2.5B-Thinking 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.
- Hy3 Preview has the larger published context window at 256K.

## Model Snapshot

| Property | Hy3 Preview | Mellum2.1-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | Tencent | JetBrains |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 256K | 128K |
| Independent public score (not head-to-head) | 51.03 | null |
| Benchmarks Covered | 6 | 7 |
| Pricing (input/output) | $0.00 / $0.00 | $0.00 / $0.00 |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Hy3 Preview public-lane score: Coming soon
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Hy3 Preview | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 54.4% | Coming soon | Coming soon |
| Gert Labs | 36.91% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | Coming soon | 17.4% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Hy3 Preview public-lane score: 29.4 (Estimated · #95/146)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Hy3 Preview | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 74.4% | 47% | Hy3 Preview |
| Terminal-Bench 2.0 | 54.4% | Coming soon | Coming soon |
| LiveCodeBench v6 | Coming soon | 82.0% | Coming soon |
| SWE-bench Pro | Coming soon | 28% | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Hy3 Preview public-lane score: 42.2 (Estimated · #97/174)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Hy3 Preview | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 87.2% | Coming soon | Coming soon |
| GPQA-D | 87.2% | 64.6% | Hy3 Preview |
| MMLU-Redux | Coming soon | 87.8% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Hy3 Preview public-lane score: 46.1 (#89/125)
- Mellum2.1-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Hy3 Preview | Mellum2.1-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFEval | Coming soon | 90.6% | Coming soon |

## FAQ

### Is there enough evidence to pick between Hy3 Preview and Mellum2.1-12B-A2.5B-Thinking?

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

- [Hy3 Preview vs Hy3](/compare/hy3-vs-hy3-preview)
- [Mellum2.1-12B-A2.5B-Thinking vs Hy3](/compare/hy3-vs-mellum2-1-12b-a2-5b-thinking)
- [Hy3 Preview vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-hy3-preview)
- [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

- [Hy3 Preview profile](/models/hy3-preview)
- [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)