Head-to-head comparison across 4benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Opus 4.5
76
Kimi K2.5 (Reasoning)
76
Verified leaderboard positions: Claude Opus 4.5 #13 · Kimi K2.5 (Reasoning) unranked
Treat this as a split decision. Claude Opus 4.5 makes more sense if agentic is the priority or you need the larger 200K context window; Kimi K2.5 (Reasoning) is the better fit if knowledge is the priority or you want the cheaper token bill.
Agentic
+7.9 difference
Coding
+10.9 difference
Knowledge
+21.1 difference
Multimodal
+8.5 difference
Claude Opus 4.5
Kimi K2.5 (Reasoning)
$5 / $25
$0.6 / $3
46 t/s
N/A
1.01s
N/A
200K
128K
Treat this as a split decision. Claude Opus 4.5 makes more sense if agentic is the priority or you need the larger 200K context window; Kimi K2.5 (Reasoning) is the better fit if knowledge is the priority or you want the cheaper token bill.
Claude Opus 4.5 and Kimi K2.5 (Reasoning) finish on the same provisional overall score, so this is less about a single winner and more about where the edge shows up. The provisional headline says tie; the benchmark table is where the real choice happens.
Claude Opus 4.5 is also the more expensive model on tokens at $5.00 input / $25.00 output per 1M tokens, versus $0.60 input / $3.00 output per 1M tokens for Kimi K2.5 (Reasoning). That is roughly 8.3x on output cost alone. Kimi K2.5 (Reasoning) is the reasoning model in the pair, while Claude Opus 4.5 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. Claude Opus 4.5 gives you the larger context window at 200K, compared with 128K for Kimi K2.5 (Reasoning).
Claude Opus 4.5 and Kimi K2.5 (Reasoning) are tied on the provisional overall score, so the right pick depends on which category matters most for your use case.
Kimi K2.5 (Reasoning) has the edge for knowledge tasks in this comparison, averaging 87.3 versus 66.2. Inside this category, AA-HLE is the benchmark that creates the most daylight between them.
Kimi K2.5 (Reasoning) has the edge for coding in this comparison, averaging 76.8 versus 65.9. Inside this category, Terminal-Bench Hard 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, GDPval-AA is the benchmark that creates the most daylight between them.
Kimi K2.5 (Reasoning) has the edge for multimodal and grounded tasks in this comparison, averaging 78.5 versus 70. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
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