Kimi K3 Fast vs GPT-6 Luna
moonshotai/kimi-k3-fast-api · openai/gpt-6-luna
As of November 5, 2026, GPT-6 Luna is the cheaper API on UberLLM: $0.0029 per million input tokens and $0.0146 per million output, versus $3.55 / $17.77 for Kimi K3 Fast, about 100% less when output is 3 tokens for every input token. These are the best prices on the market right now. Both work with one OpenAI-compatible key and UberLLM adds no fee. Choose GPT-6 Luna to cut cost; choose Kimi K3 Fast when its capabilities fit your task better.
Kimi K3 Fast vs GPT-6 Luna, side by side
| Spec | Kimi K3 Fast | GPT-6 Luna |
|---|---|---|
| Price · input / 1M | $3.55 | $0.0029 |
| Price · output / 1M | $17.77 | $0.0146 |
| Context length | 1,000,000 | 1,050,000 |
| Max output tokens | 131,072 | 128,000 |
| Input modalities | text, image | text, image, file |
| Output modalities | text | text |
| Tools / functions | Yes | Yes |
| Vision (image input) | Yes | Yes |
| Reasoning | Yes | Yes |
| % off list | 21% off | 97.1% off |
Best prices on UberLLM right now. No UberLLM fee on requests; adding credit by card costs 5.5% + $0.50. Updated November 5, 2026. A price more than 70% below list is what buyers were billed, not an error. Why so cheap?
Kimi K3 Fast vs GPT-6 Luna — FAQ
Is Kimi K3 Fast or GPT-6 Luna cheaper?
GPT-6 Luna is cheaper on a blended token mix, by about 100%. A request costs what its provider charged, UberLLM adds no fee, and every request is listed with its cost in Activity.
What's the price difference between Kimi K3 Fast and GPT-6 Luna?
Kimi K3 Fast: $3.55 in / $17.77 out per 1M tokens. GPT-6 Luna: $0.0029 in / $0.0146 out per 1M tokens. That's roughly a 100% blended difference. Prices are live; UberLLM adds no fee.
Can I use both Kimi K3 Fast and GPT-6 Luna with one API?
Yes. Both are served through a single OpenAI-compatible endpoint — set the base URL to https://api.uberllm.dev/v1 and your UberLLM key, then switch between them by changing the model id. Anthropic SDKs work via https://api.uberllm.dev/v1/messages.