Head-to-head comparison across 3benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Grok 4.20
71
Kimi K2.5 (Reasoning)
75
Pick Kimi K2.5 (Reasoning) if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if you need the larger 2M context window.
Agentic
+7.5 difference
Coding
+15.8 difference
Multimodal
+7.7 difference
Grok 4.20
Kimi K2.5 (Reasoning)
$2 / $6
$0.6 / $3
233 t/s
N/A
10.33s
N/A
2M
128K
Pick Kimi K2.5 (Reasoning) if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if you need the larger 2M context window.
Kimi K2.5 (Reasoning) is clearly ahead on the provisional aggregate, 75 to 71. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Kimi K2.5 (Reasoning)'s sharpest advantage is in coding, where it averages 76.8 against 61. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 47.1% to 50.8%.
Grok 4.20 is also the more expensive model on tokens at $2.00 input / $6.00 output per 1M tokens, versus $0.60 input / $3.00 output per 1M tokens for Kimi K2.5 (Reasoning). That is roughly 2.0x on output cost alone. Grok 4.20 gives you the larger context window at 2M, compared with 128K for Kimi K2.5 (Reasoning).
Kimi K2.5 (Reasoning) is ahead on BenchLM's provisional leaderboard, 75 to 71. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 47.1% and 50.8%.
Kimi K2.5 (Reasoning) has the edge for coding in this comparison, averaging 76.8 versus 61. Inside this category, Vibe Code Bench is the benchmark that creates the most daylight between them.
Kimi K2.5 (Reasoning) has the edge for agentic tasks in this comparison, averaging 54.6 versus 47.1. Inside this category, Gert Labs 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 70.8. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.
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