Mellum2-12B-A2.5B-Thinking: benchmark scores, price and ranking

Mellum2-12B-A2.5B-Thinking from JetBrains ranks #347 of 743 LLMs on the LLMs Tiger aggregate benchmark score (48.5), based on 1 benchmark results captured up to 2026-10-13.

Organisation: JetBrains
Type: Open-weight / local model
Open weights: Yes
Aggregate rank: #347 of 743 (score 48.5)

Across the 1 benchmark where at least ten models are scored, Mellum2-12B-A2.5B-Thinking is in the top 10% on 0 and in the top half on 0.

Mellum2-12B-A2.5B-Thinking benchmark results

Mellum2-12B-A2.5B-Thinking benchmark scores, ranked against all models measured on each benchmark
Benchmark	Score	Rank	Source	Captured
GPQA Diamond	57.6%	#169 of 275	HuggingFace GPQA Diamond leaderboard	2026-10-13

About Mellum2-12B-A2.5B-Thinking

Mellum2-12B-A2.5B-Thinking is an open-weight model that can run on your own hardware from JetBrains. No API price is listed for it yet. We hold 1 benchmark result for it across 1 area, and none is in the top tenth of its board.

Where Mellum2-12B-A2.5B-Thinking stands

On our aggregate score, Mellum2-12B-A2.5B-Thinking is #347 of 743 ranked models, around the middle of the table. Its score is 48.5; the scale is centred on 50, so it sits 1.5 points below the typical model. That beats 53% of the ranked field. Among the 6 ranked JetBrains models it is #1. The next one down is Mellum2-12B-A2.5B-Instruct at 46.8.

Mellum2-12B-A2.5B-Thinking, benchmark by benchmark

Mellum2-12B-A2.5B-Thinking lands below the middle on GPQA Diamond: 57.6%, #169 of 275, with 61% of the field scoring higher. GPT-6 Astra (max) leads at 95.8%; the closest result above is DeepSeek-V3 at 58.2%. It covers expert-level science questions. The board median is 71.7%, so Mellum2-12B-A2.5B-Thinking is 14.1 points below it. Source: HuggingFace GPQA Diamond leaderboard, captured 2026-10-13.

Reading these numbers

The 1 score on this page comes from 1 source: HuggingFace GPQA Diamond leaderboard (1). No official leaderboard supplied any of them, so treat them as third-party measurements. With 1 results the aggregate rank can move a lot when one new score arrives.