Kimi K3 vs Kimi K2.7

What I tested — same prompt, two models

I run the same fixed prompt set through every new model the day it drops — same string, one shot, single HTML file out — and I score the result 0–10 on whether it ran, how close it hit the brief, and how good it looked. Below is what came out when I gave the exact same prompts to Kimi K3 and Kimi K2.7, side by side, on 38 shared tasks inside the Agent Operating System.

Both models were given identical prompts inside the Agent Operating System — no help, no iteration, no "best of N" tricks. I run each prompt once, save the HTML file the model produces, and score it 0–10 on whether it ran, how close it hit the brief, and how good it looked. The scoring is mine. The verdicts below are pulled from my source comparison guides at agentos.guide where I publish every score and the reasoning behind it.

Kimi K3 · Wired into the Agent OS as the `kimi-k3` Hermes profile and a K3 speed-toggle in the Kimi Code tab — used for long unattended agent runs where a slow-but-right model beats a fast-but-forgetful one.

Kimi K2.7 · Wired into the Agent OS as the heavy-lifter for game/sim prototypes and Kanban-dispatched code work. Mode toggled per task: Quality for one-shot games, Fast for short bursts.

Where Kimi K3 beat Kimi K2.7

The tasks where I gave Kimi K3 a higher 0–10 score on the same prompt — with the actual commentary from my source guides.

Where Kimi K2.7 beat Kimi K3

The tasks where I gave Kimi K2.7 a higher 0–10 score on the same prompt — with the actual commentary from my source guides.

Strengths & weaknesses I logged

Pricing & context — the spec sheet

The verdict — which should you pick?

Across 19 scored shared tasks, the averages are essentially tied — Kimi K3 7.64 vs Kimi K2.7 7.34. This isn't the comparison where one wins; it's the comparison where you pick based on context, pricing, and what you're actually trying to ship.

If you only run one of these inside your stack, the head-to-head average above is the call. If you can run both, my honest play is to wire Kimi K3 and Kimi K2.7 both into the Agent Operating System and dispatch each from the kanban by task type — long-horizon agent runs → Kimi K3, interactive game prototypes you want shippable on the first prompt → Kimi K2.7. That's the same setup I run for the 4,000+ founders inside the AI Profit Boardroom.

FAQ — Kimi K3 vs Kimi K2.7

Which is better, Kimi K3 or Kimi K2.7?

On Goldie Bench, Kimi K3 averages 7.64/10 across the shared tasks, with 9 gold, 8 silver, 7 bronze overall. Kimi K2.7 averages 7.34/10, with 2 gold, 1 silver, 1 bronze. Kimi K3 wins the head-to-head 12–7.

How much does Kimi K3 cost vs Kimi K2.7?

Kimi K3: Launched July 16, 2026. 2.5T-param MoE. $3/M input on OpenRouter at launch; included at no extra cost in the Kimi coding plan (`k3` on the coding endpoint). Kimi K2.7: Available on Moonshot's flat-rate subscription plan — no per-token billing for individual builders. The plan covers all three speed modes (Fast, No-Think, Quality). Vendor: Moonshot AI (moonshot.ai), based in Beijing.

What's the context window for Kimi K3 vs Kimi K2.7?

Kimi K3 has a 1,048,576 tokens — a full codebase in working memory context window. Kimi K2.7 has a 256,000 tokens context window.

When should I pick Kimi K3 over Kimi K2.7?

Pick Kimi K3 for: long-horizon agent runs; whole-repo context work; terminal-driving agents. The trade-off is the weaknesses we logged on the bench: Slow on hard tasks — early testers report up to ~35 minutes at max reasoning; this bench saw 13+ minute single builds; Launch-day rate limits on OpenRouter (429s) — the coding-plan endpoint was the reliable route; Self-reports as K2.7 if you ask it — verify the served model via the API response, not the model's word.

When should I pick Kimi K2.7 over Kimi K3?

Pick Kimi K2.7 for: Interactive game prototypes you want shippable on the first prompt; High-iteration agent loops where per-token cost would dominate; Long-context refactors using the 256K window inside Agent OS. The trade-off is the weaknesses we logged on the bench: Plays plainest on abstract visual prompts — synthwave grids, fluid sims, aurora — where GLM and Opus add more flair; Bronze average on the {{SITE_NAME}} bench despite the gold-medal games — its visual builds are accurate but understated.

How does Goldie Bench score Kimi K3 vs Kimi K2.7?

Every demo on this page was built by Julian Goldie inside the Agent Operating System — same fixed prompt for both models, one shot, single HTML file out. Each result gets a 0–10 score on whether it ran, how close it hit the brief, and how good it looked. The highest score on each task gets gold; second gets silver; third gets bronze. See methodology for full provenance.

Related comparisons

Other head-to-heads using the same scoring system:

Full model pages: Kimi K3 · Kimi K2.7 · back to the leaderboard