Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Haiku 4.5
56
Mellum2-12B-A2.5B-Instruct
27
Pick Claude Haiku 4.5 if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Instruct only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.
Coding
+36.1 difference
Claude Haiku 4.5
Mellum2-12B-A2.5B-Instruct
$1 / $5
N/A
N/A
N/A
N/A
N/A
200K
128K
Pick Claude Haiku 4.5 if you want the stronger benchmark profile. Mellum2-12B-A2.5B-Instruct only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.
Claude Haiku 4.5 is clearly ahead on the provisional aggregate, 56 to 27. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Haiku 4.5's sharpest advantage is in coding, where it averages 73.3 against 37.2.
Claude Haiku 4.5 gives you the larger context window at 200K, compared with 128K for Mellum2-12B-A2.5B-Instruct.
Claude Haiku 4.5 is ahead on BenchLM's provisional leaderboard, 56 to 27.
Claude Haiku 4.5 has the edge for coding in this comparison, averaging 73.3 versus 37.2. Mellum2-12B-A2.5B-Instruct stays close enough that the answer can still flip depending on your workload.
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