Kimi K3 vs GLM-5
Should you write with Kimi K3 or GLM-5? 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 82.8.
The verdict
Both are open weights, so the only question is quality against cost, and quality goes firmly to Kimi K3. It's #21 against #66, and it wins all nine metrics. The biggest gaps are Length Adherence, over eleven points, and Continuity & Emotion, about seven, so GLM-5 scripts drift further from the target length and score lower on keeping the thread. GLM-5 costs about $0.050 a script against $0.260, and that's real money at scale. But if you like the GLM family, look at GLM-5.3 instead: it ranks above both of these. GLM-5 only makes sense when you're locked to that exact model.
Pick Kimi K3 when you want open-weights scripts that stay on length and keep their thread.
Pick GLM-5 only when you're tied to that exact model and the lower price outweighs the quality gap.
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 GLM-5, 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, Continuity & Emotion does the most to put Kimi K3 ahead: it leads there by 7.4 points. If you care about one thing, say voice or length, go straight to that row.
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 5.2x as much per script as GLM-5.
| Kimi K3 | GLM-5 | |
|---|---|---|
| Overall / 100 | 88.5 | 82.8 |
| Writing Elo | 2217 | 1692 |
| Score spread across drafts (± overall std) | 1.260 | 2.400 |
| Cost per script (USD) | 0.260 | 0.050 |
| Avg time per script (min) | 3.9 | 3.1 |
| Open weights | Yes | Yes |
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 · GLM-5. The whole scoring pipeline is on the methodology page.
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