Model comparison
Claude Sonnet 4.5 Thinking vs Mellum2-12B-A2.5B-Thinking
Head-to-head evidence from 0 shared benchmark results across 0 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.
Evidence parity. Claude Sonnet 4.5 Thinking and Mellum2-12B-A2.5B-Thinking share 0 comparable benchmark results. 0 of 8 categories are comparable. 2 results are unique to Claude Sonnet 4.5 Thinking; 5 to Mellum2-12B-A2.5B-Thinking.
Updated July 23, 2026- Shared results
- 0
- Claude Sonnet 4.5 Thinking only
- 2
- Mellum2-12B-A2.5B-Thinking only
- 5
- Comparable categories
- 0 / 8
Benchmark data for Claude Sonnet 4.5 Thinking and Mellum2-12B-A2.5B-Thinking is coming soon on BenchLM.
Confidence note. This is a partial-evidence comparison with 0 shared benchmark results across 0 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.
Why this result
BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.
Claude Sonnet 4.5 Thinking has the larger context window at 200K, compared with 128K for Mellum2-12B-A2.5B-Thinking.
Operational comparison
Runtime and commercial metrics are compared only when both models have a complete sourced value.
| Metric | Claude Sonnet 4.5 Thinking | Mellum2-12B-A2.5B-Thinking | Comparison |
|---|---|---|---|
| Input / output priceUSD per 1M tokens | Claude Sonnet 4.5 ThinkingNot available | Mellum2-12B-A2.5B-ThinkingNot available | A complete price comparison is not available. |
| Generation speedtokens per second | Claude Sonnet 4.5 ThinkingNot available | Mellum2-12B-A2.5B-ThinkingNot available | A complete speed comparison is not available. |
| First-answer latencyseconds to first token | Claude Sonnet 4.5 ThinkingNot available | Mellum2-12B-A2.5B-ThinkingNot available | A complete latency comparison is not available. |
| Context windowmaximum listed tokens | Claude Sonnet 4.5 Thinking200K | Mellum2-12B-A2.5B-Thinking128K | Claude Sonnet 4.5 Thinking lists the larger context window. |
Benchmark Deep Dive
Agentic1 benchmarks
| Benchmark | Claude Sonnet 4.5 Thinking | Mellum2-12B-A2.5B-Thinking | Result |
|---|---|---|---|
| BFCL v4Source | — | 45.6% | Not comparable |
Coding1 benchmarks
| Benchmark | Claude Sonnet 4.5 Thinking | Mellum2-12B-A2.5B-Thinking | Result |
|---|---|---|---|
| Vibe Code BenchSource | 22.62% | — | Not comparable |
Knowledge3 benchmarks
Multimodal1 benchmarks
| Benchmark | Claude Sonnet 4.5 Thinking | Mellum2-12B-A2.5B-Thinking | Result |
|---|---|---|---|
| Design Arena WebsiteSource | 1219 | — | Not comparable |
Inst. Following1 benchmarks
| Benchmark | Claude Sonnet 4.5 Thinking | Mellum2-12B-A2.5B-Thinking | Result |
|---|---|---|---|
| IFEvalSource | — | 76.5% | Not comparable |
Frequently Asked Questions (2)
Can I compare Claude Sonnet 4.5 Thinking and Mellum2-12B-A2.5B-Thinking on BenchLM yet?
Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.
Why does this comparison show “coming soon”?
BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.
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