Head-to-head comparison across 4benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Opus 4.8
93
Kimi K2.5
64
Verified leaderboard positions: Claude Opus 4.8 #3 · Kimi K2.5 #14
Pick Claude Opus 4.8 if you want the stronger benchmark profile. Kimi K2.5 only becomes the better choice if multimodal & grounded is the priority or you want the cheaper token bill.
Agentic
+25.5 difference
Coding
+12.2 difference
Knowledge
+5.0 difference
Multimodal
+2.4 difference
Claude Opus 4.8
Kimi K2.5
$5 / $25
$0.6 / $3
N/A
45 t/s
N/A
2.38s
1M
256K
Pick Claude Opus 4.8 if you want the stronger benchmark profile. Kimi K2.5 only becomes the better choice if multimodal & grounded is the priority or you want the cheaper token bill.
Claude Opus 4.8 is clearly ahead on the provisional aggregate, 93 to 64. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Opus 4.8's sharpest advantage is in agentic, where it averages 80.1 against 54.6. The single biggest benchmark swing on the page is HLE, 57.9% to 30.1%. Kimi K2.5 does hit back in multimodal & grounded, so the answer changes if that is the part of the workload you care about most.
Claude Opus 4.8 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. That is roughly 8.3x on output cost alone. Claude Opus 4.8 is the reasoning model in the pair, while Kimi K2.5 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 4.8 gives you the larger context window at 1M, compared with 256K for Kimi K2.5.
Claude Opus 4.8 is ahead on BenchLM's provisional leaderboard, 93 to 64. The biggest single separator in this matchup is HLE, where the scores are 57.9% and 30.1%.
Claude Opus 4.8 has the edge for knowledge tasks in this comparison, averaging 70.1 versus 65.1. Inside this category, HLE is the benchmark that creates the most daylight between them.
Claude Opus 4.8 has the edge for coding in this comparison, averaging 76.4 versus 64.2. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.
Claude Opus 4.8 has the edge for agentic tasks in this comparison, averaging 80.1 versus 54.6. Inside this category, GDPval-AA 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 76.1. Claude Opus 4.8 stays close enough that the answer can still flip depending on your workload.
Estimates at 50,000 req/day · 1000 tokens/req average.
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