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Kimi K3 vs Grok 4.6 (high)

Should you write with Kimi K3 or Grok 4.6 (high)? On this page the only thing that changes is the model. Both wrote their own version of the scripts behind 10 of my What's AI videos, five drafts per script, and three judges from three model families scored every draft blind, with my finished script as the reference. Kimi K3 leads overall, 88.5 to 85.9.

Kimi K3
#21 Elo 2217 · 88.5/100
Grok 4.6 (high)
#53 Elo 1970 · 85.9/100
Cost / script
$0.260 vs $0.211
Human baseline
90.9 Kimi K3 falls below it · Grok 4.6 (high) falls below it

The verdict

Turning up Grok's reasoning doesn't change this matchup. Grok 4.6 (high) actually lands below plain Grok 4.6 on the board, at #53 against Kimi K3's #21. Same weakness as the default setting, too: its hook scores about twelve points below Kimi's and swings a lot from run to run, so some openings score well and some don't. Kimi also stays closer to the target length, scores higher on writing craft and is open weights. Grok 4.6 (high) does write better visual cues, and it's slightly cheaper at about $0.211 a script against $0.260, so it works when cues are what you need and you'll rewrite the opening anyway.

Pick Kimi K3 when you want reliable openings and on-length scripts from an open-weights model.
Pick Grok 4.6 (high) when visual cues are the priority and you'll rework the hook by hand.

How to read these numbers

Overall vs Elo. Overall is the weighted rubric score. Elo compares each model's five-draft average with every other model's, script by script, and counts gaps inside run-to-run noise as draws, so it rewards winning often and can disagree with overall. My own scripts score 90.9 on the same rubric, not a literal 100. Right now 2 of 167 ranked configurations reach it. A model above that line writes at that level on this rubric. That's not the same as beating my script line for line.

Reading the Elo intervals. Each 95% range comes from resampling every model's recorded run scores on each task and re-ranking. Comparing these separate ranges does not test the Elo gap between two models: far apart is strong evidence, and overlap isn't a tie. The tasks stay fixed, so the ranges say nothing about new tasks (the long version).

Metric by metric: where the gap comes from

Blue is Kimi K3, orange is Grok 4.6 (high), and the solid bar takes the metric. The weight under each name is how much it counts toward the overall. Weighted by how much each metric counts, Hook Strength does the most to put Kimi K3 ahead: it leads there by 11.9 points. If you care about one thing, say voice or length, go straight to that row.

Tone & Voice Match19% weight
88.4
87.5
Writing Craft & Clarity13% weight
89.0
85.9
Substance, Accuracy & Value15% weight
87.6
86.6
Continuity & Emotion14% weight
87.6
86.0
YouTube Best Practices12% weight
88.4
86.8
Hook Strength10% weight
89.2
77.3
Length Adherence8% weight
90.1
85.6
Slop Score (EQ-Bench + ours)5% weight
91.2
91.0
Visual Cue Quality4% weight
85.1
88.2

Cost, speed, and consistency

Quality is half the decision. The other half is what each script costs you, how long you wait, and how often you get a bad draft. The lead has a price: Kimi K3 costs about 1.2x as much per script as Grok 4.6 (high).

Kimi K3Grok 4.6 (high)
Overall / 10088.585.9
Writing Elo22171970
Score spread across drafts (± overall std)1.2602.980
Cost per script (USD)0.2600.211
Avg time per script (min)3.93.6
Open weightsYesNo

Green wins the row, and for spread, cost and time, lower wins. Cost is one script at recorded list prices, uncached and without judging, so your real bill will differ. Spread is how much the overall score moves across a model's drafts, and time is the average time to get one accepted script, retries included.

Want the script-by-script detail? Full scorecards: Kimi K3 · Grok 4.6 (high). The whole scoring pipeline is on the methodology page.

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