The first model of Moonshot AI's K3.1 series and its most capable Kimi to date: a 3T-class reasoning model with native vision and a 1M-token context. It costs a third less per token than Kimi K3; Moonshot says full weights ship by November 4, 2026.
Pick it if
you want Moonshot's current flagship at a lower rate than Kimi K3
your prompts outgrow the 256K context of Kimi 2.6 and 2.7 Code
you resend long prompts, so cache hits bill at a tenth of input
Skip it if
you need temperature or top_p control: they are fixed
Kimi 2.6 or 2.7 Code covers your workload at a lower rate
Anthropic's mid-tier Claude model, which Anthropic describes as its best combination of speed and intelligence. It succeeds Sonnet 5 at the same $2 / $10 rate, with a 1M-token context and half the cache-read price, and sits below Opus 5.5.
Pick it if
you want Claude at half of Opus 5.5's per-token price
you resend long prompts; cache hits bill at 5% of input
your prompts need a 1M-token window at the standard rate
Skip it if
Haiku 5.5 handles your high-volume classification or routing more cheaply
your code forces tool use or sets temperature; both return errors
FAQ
Which is better, Kimi K3.1 Pro or Claude Sonnet 5.5?
On Terminal-Bench 4.0, as each maker reports it, Kimi K3.1 Pro scores 65.7% and Claude Sonnet 5.5 70.6%. These are each maker's own numbers, not a controlled head-to-head; the spec table lists every benchmark both publish.
Which is cheaper, Kimi K3.1 Pro or Claude Sonnet 5.5?
Kimi K3.1 Pro and Claude Sonnet 5.5 list the same input and output prices. On a coding-agent session (2M tokens in, 60,000 out) Kimi K3.1 Pro costs $4.60 and Claude Sonnet 5.5 $4.60.
Can I switch between Kimi K3.1 Pro and Claude Sonnet 5.5 mid-task?
Yes. In an Octomind session, /model octohub:kimi-k3.1-pro and /model octohub:claude-sonnet-5-5 switch models without losing the conversation, so you can draft on one and review on the other.
Try either model
Switch between models inside the same Octomind session.