Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
LongCat-2.0
80
Mellum2-12B-A2.5B-Instruct
26
Pick LongCat-2.0 if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Instruct only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.
Coding
+22.3 difference
LongCat-2.0
Mellum2-12B-A2.5B-Instruct
$0.75 / $2.95
N/A
N/A
N/A
N/A
N/A
1M
128K
Pick LongCat-2.0 if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Instruct only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.
LongCat-2.0 is clearly ahead on the provisional aggregate, 80 to 26. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
LongCat-2.0's sharpest advantage is in coding, where it averages 59.5 against 37.2.
LongCat-2.0 is the reasoning model in the pair, while Mellum2-12B-A2.5B-Instruct is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. LongCat-2.0 gives you the larger context window at 1M, compared with 128K for Mellum2-12B-A2.5B-Instruct.
LongCat-2.0 is ahead on BenchLM's provisional leaderboard, 80 to 26.
LongCat-2.0 has the edge for coding in this comparison, averaging 59.5 versus 37.2. Mellum2-12B-A2.5B-Instruct stays close enough that the answer can still flip depending on your workload.
For engineers, researchers, and the plain curious — a weekly brief on new models, ranking shifts, and pricing changes.
Free. No spam. Unsubscribe anytime.