Head-to-head comparison across 7benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Opus 4.5
80
Kimi K2.5
68
Verified leaderboard positions: Claude Opus 4.5 #5 · Kimi K2.5 #11
Pick Claude Opus 4.5 if you want the stronger benchmark profile. Kimi K2.5 only becomes the better choice if instruction following is the priority.
Agentic
+7.9 difference
Coding
+6.9 difference
Reasoning
+3.4 difference
Knowledge
+1.1 difference
Multilingual
+3.4 difference
Multimodal
+7.9 difference
Inst. Following
+14.5 difference
Claude Opus 4.5
Kimi K2.5
$null / $null
$0.5 / $2.8
46 t/s
45 t/s
1.01s
2.38s
200K
128K
Pick Claude Opus 4.5 if you want the stronger benchmark profile. Kimi K2.5 only becomes the better choice if instruction following is the priority.
Claude Opus 4.5 is clearly ahead on the provisional aggregate, 80 to 68. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Opus 4.5's sharpest advantage is in agentic, where it averages 62.5 against 54.6. The single biggest benchmark swing on the page is Toolathlon, 43.5% to 27.8%. Kimi K2.5 does hit back in instruction following, so the answer changes if that is the part of the workload you care about most.
Claude Opus 4.5 gives you the larger context window at 200K, compared with 128K for Kimi K2.5.
Claude Opus 4.5 is ahead on BenchLM's provisional leaderboard, 80 to 68. The biggest single separator in this matchup is Toolathlon, where the scores are 43.5% and 27.8%.
Claude Opus 4.5 has the edge for knowledge tasks in this comparison, averaging 66.2 versus 65.1. Inside this category, MMLU-Pro is the benchmark that creates the most daylight between them.
Claude Opus 4.5 has the edge for coding in this comparison, averaging 65.9 versus 59. Inside this category, SWE Multilingual is the benchmark that creates the most daylight between them.
Claude Opus 4.5 has the edge for reasoning in this comparison, averaging 64.4 versus 61. Inside this category, LongBench v2 is the benchmark that creates the most daylight between them.
Claude Opus 4.5 has the edge for agentic tasks in this comparison, averaging 62.5 versus 54.6. Inside this category, Toolathlon is the benchmark that creates the most daylight between them.
Kimi K2.5 has the edge for multimodal and grounded tasks in this comparison, averaging 78.5 versus 70.6. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
Kimi K2.5 has the edge for instruction following in this comparison, averaging 93.9 versus 79.4. Inside this category, IFEval is the benchmark that creates the most daylight between them.
Claude Opus 4.5 has the edge for multilingual tasks in this comparison, averaging 85.7 versus 82.3. Inside this category, MMLU-ProX is the benchmark that creates the most daylight between them.
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