Kimi K3 vs GPT-5.6 Sol

Kimi K3 and GPT-5.6 Sol are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Kimi K3, from MoonshotAI, has a 1,048,576-token context window, costs from $2.70/1M input and $13.50/1M output tokens across 4 providers and scores 43.6 on the Artificial Analysis Intelligence Index.

GPT-5.6 Sol, from OpenAI, has a 1,050,000-token context window, costs $4.00/1M input and $20.00/1M output tokens and scores 42.3 on the Artificial Analysis Intelligence Index.

Kimi K3 is the cheapest on input, 1.5× cheaper than the next model, GPT-5.6 Sol has the largest context window, Kimi K3 scores highest for intelligence, GPT-5.6 Sol leads on coding and Kimi K3 has the highest throughput.