Claude Opus 4.8 vs Kimi K3

Claude Opus 4.8 and Kimi K3 are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Claude Opus 4.8, from Anthropic, has a 1,000,000-token context window, costs from $5.00/1M input and $25.00/1M output tokens across 3 providers and scores 41.8 on the Artificial Analysis Intelligence Index.

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.

Kimi K3 is the cheapest on input, 1.9× cheaper than the next model, Kimi K3 has the largest context window, Kimi K3 scores highest for intelligence, Kimi K3 leads on coding and Claude Opus 4.8 has the highest throughput.