Comparisons › Kimi vs ChatGPT: open-weight reasoning vs GPT

Kimi vs ChatGPT: open-weight reasoning vs GPT

Kimi K3 is the surprise of the open-weight world — top-tier design and reasoning at a fraction of OpenAI's flagship price.

Value verdict: on intelligence per $1, Kimi currently comes out ahead — 36,667 vs 13,250. Prices move often, so recheck the calculator regularly.

At a glance

Model compared

Kimi	ChatGPT	ChatGPT
Flagship model	Kimi K3	GPT-6 Astra
Input / 1M	$3	$10
Output / 1M	$15	$50
Intelligence index	44	53
Tokens / $1	83.3k	25.0k
Intelligence / $1	36,667	13,250
Cheapest plan	—	ChatGPT Plus ($20/mo)

API pricing

Kimi K3 costs $3 / $15 per 1M tokens against GPT-6 Astra's $10 / $50 — Kimi is more than 3x cheaper on output. It also undercuts GPT-5.6 Sol ($4 / $20) on both input and output, and open weights mean you can self-host it.

Capabilities

Practitioners rate Kimi K3 as the best open-weight model on the market, with standout front-end design and game-dev skills. GPT-6 Astra is OpenAI's new top tier — level with Claude Fable 5.1 at the top of our intelligence index — and brings the wider OpenAI tooling ecosystem, though OpenAI's models still need close guidance for design.

The verdict

Kimi K3 wins on open-weight freedom, design and one-shot reliability for its class; GPT-6 Astra wins on ecosystem maturity and raw back-end power. Both are strong — pick by whether you value open weights or OpenAI's tooling.

Bottom line: Kimi K3 delivers top-tier reasoning and design at a lower price with open weights; GPT-6 Astra brings the wider OpenAI ecosystem and raw back-end power. Choose open weights and value, or OpenAI's tooling.