Kimi K2.6 vs Kimi K3

What are we comparing?

Kimi K2.6 and Kimi K3 are two open-weight models that you can install on your own servers, both built by Moonshot AI. Kimi K2.6 was released on April 20, 2026, Kimi K3 on July 16, 2026.

All figures below come from public sources checked on October 22, 2026: models.dev and OpenRouter for prices and capabilities, Epoch AI for scores.

Which one is more capable?

On our capability index, Kimi K2.6 scores 84.4 out of 100 and Kimi K3 80.7. Kimi K2.6 leads by 3.7 points.

On the 3 benchmarks reported for both, Kimi K2.6 wins 0 times and Kimi K3 3:

• GPQA Diamond (PhD-level science questions): Kimi K2.6 90.8%, Kimi K3 93.1%
• OTIS Mock AIME (competition mathematics problems): Kimi K2.6 96.1%, Kimi K3 97.2%
• FrontierMath (very hard research-level mathematics): Kimi K2.6 57.2%, Kimi K3 72.2%

Which one costs less?

Kimi K2.6 costs $0.95 per million input tokens and $4 per million output tokens; Kimi K3 costs $3 and $15.

For a typical agent task (read 20,000 tokens, write 2,000), expect $0.027 with Kimi K2.6 versus $0.09 with Kimi K3. Kimi K2.6 is 3.3 times cheaper, a gap that adds up quickly over 1,000 tasks: $63 difference.

Run the numbers with your own volumes in the agent cost calculator.

Context and capabilities

Kimi K3 reads more in one go: 1,048,576 tokens of context (roughly 1,573 pages), versus 262,144 for Kimi K2.6.

Reasoning mode: Kimi K2.6 yes, Kimi K3 yes. Tool calling: Kimi K2.6 yes, Kimi K3 yes. Image input: Kimi K2.6 yes, Kimi K3 yes.

Both publish their weights: you can host them yourself.

In short

Our reading of the data:

• Choose Kimi K2.6 for a higher capability index and a lower cost.
• Choose Kimi K3 for a larger context window and a more recent release.

This verdict relies on public figures; it does not replace a trial on your own tasks.