# Agents-A1-4B vs Mellum2-12B-A2.5B-Thinking

> Side-by-side benchmark comparison for Agents-A1-4B and Mellum2-12B-A2.5B-Thinking across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/agents-a1-4b-vs-mellum2-12b-a2-5b-thinking
- Last updated: September 10, 2026

- Shared sourced benchmarks: 2
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Evidence is too thin for a benchmark verdict: Agents-A1-4B and Mellum2-12B-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.
- Agents-A1-4B has the larger published context window at 262K.

## Model Snapshot

| Property | Agents-A1-4B | Mellum2-12B-A2.5B-Thinking |
|----------|----------|----------|
| Creator | InternScience | JetBrains |
| Type | Open Weight | Open Weight |
| Reasoning | Reasoning | Reasoning |
| Context | 262K | 128K |
| Independent public score (not head-to-head) | null | null |
| Benchmarks Covered | 11 | 6 |
| Pricing (input/output) | $0.00 / $0.00 | N/A |

## Category Breakdown

### Agentic

- Winner: Insufficient shared evidence
- Agents-A1-4B public-lane score: Coming soon
- Mellum2-12B-A2.5B-Thinking public-lane score: 45.8 (Estimated · #79/152)

| Benchmark | Agents-A1-4B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| BrowseComp | 66.8% | Coming soon | Coming soon |
| GAIA | 95.1% | Coming soon | Coming soon |
| MLE-Bench Lite | 22.7% | Coming soon | Coming soon |
| τ²-bench results | 78.2% | Coming soon | Coming soon |
| VITA-Bench | 40.3% | Coming soon | Coming soon |
| BFCL v4 | Coming soon | 45.6% | Coming soon |

### Coding

- Winner: Insufficient shared evidence
- Agents-A1-4B public-lane score: Coming soon
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Agents-A1-4B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| SciCode | 29.6% | Coming soon | Coming soon |
| LiveCodeBench v6 | 59.6% | 69.9% | Mellum2-12B-A2.5B-Thinking |

### Reasoning

- Winner: Insufficient shared evidence
- Agents-A1-4B public-lane score: Coming soon
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Agents-A1-4B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| LongBench v2 | 52.1% | Coming soon | Coming soon |

### Knowledge

- Winner: Insufficient shared evidence
- Agents-A1-4B public-lane score: Coming soon
- Mellum2-12B-A2.5B-Thinking public-lane score: 46.3 (Estimated · #103/183)

| Benchmark | Agents-A1-4B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| FrontierScience Research | 33.3% | Coming soon | Coming soon |
| MMLU-Redux | Coming soon | 86.2% | Coming soon |
| GPQA | Coming soon | 57.6% | Coming soon |
| GPQA-D | Coming soon | 57.6% | Coming soon |

### Instruction Following

- Winner: Insufficient shared evidence
- Agents-A1-4B public-lane score: Coming soon
- Mellum2-12B-A2.5B-Thinking public-lane score: Coming soon

| Benchmark | Agents-A1-4B | Mellum2-12B-A2.5B-Thinking | Winner |
|-----------|-----------|-----------|--------|
| IFBench | 69.1% | Coming soon | Coming soon |
| IFEval | 94.8% | 76.5% | Agents-A1-4B |

## FAQ

### Is there enough evidence to pick between Agents-A1-4B and Mellum2-12B-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

- [Agents-A1-4B vs Agents-A1](/compare/agents-a1-vs-agents-a1-4b)
- [Mellum2-12B-A2.5B-Thinking vs Agents-A1](/compare/agents-a1-vs-mellum2-12b-a2-5b-thinking)
- [Agents-A1-4B vs Agents-A1-F16-GGUF](/compare/agents-a1-4b-vs-agents-a1-f16-gguf)
- [Mellum2-12B-A2.5B-Thinking vs Agents-A1-F16-GGUF](/compare/agents-a1-f16-gguf-vs-mellum2-12b-a2-5b-thinking)

## Explore More

- [Agents-A1-4B profile](/models/agents-a1-4b)
- [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)