Kimi K2.8 Preview
Overview
Kimi K2.8 Preview is Moonshot AI's K2-series preview model for coding and agent workflows, released on September 11, 2026. Available through the API as kimi-k2.8-preview, it combines a 1,048,576-token context window, image and video understanding, and adjustable reasoning. Moonshot AI describes its overall performance as close to Kimi K3, with more efficient thinking than K2.7 Code.
Key Features
- Coding and Agent Focus: Designed for code completion and everyday development, with provider-reported improvements in coding and agent capabilities over K2.7 Code.
- Adjustable Reasoning: Supports
low,high, andmaxthinking effort, withmaxas the default. Thinking can also be disabled. - 1M Context Window: Accommodates large codebases, supporting documents, and extended conversation history within a 1,048,576-token context window.
- Visual Inputs: Accepts images and video alongside text, enabling development tasks that use screenshots, interface references, or recorded behavior.
Best Use Cases
- Everyday Software Development: Code completion, feature implementation, debugging, and test generation, using adjustable reasoning to match task complexity.
- Repository Analysis and Refactoring: Reviewing dependencies and coordinating changes across files with substantial code and documentation in context.
- Visually Guided Development: Interpreting UI screenshots or screen recordings to guide implementation and investigate reported problems.
Capabilities and Limitations
| Capability | Description |
|---|---|
| Reasoning | Supports low, high, or max; defaults to max. Thinking can also be disabled. |
| Multimodal | Supports text, image, and video input with text output. |
| Context Window | 1,048,576 tokens. |
| Max Output | Not published. |
| Tool Use | Supports interactive coding agents that read files, edit code, and execute commands through client-provided tools. |
Known Limitations
- Published specifications do not currently include K2.8-specific parameter counts, architecture details, a knowledge cutoff, or numerical benchmark results. The comparison with Kimi K3 is qualitative.
Standard Pricing
The token prices below are shown in USD per 1 million tokens; web search is billed in USD per use.
| Model | Input (USD / 1M Tokens) | Cache Write (USD / 1M Tokens) | Cache Read (USD / 1M Tokens) | Output (USD / 1M Tokens) | Web Search (USD / use) |
|---|---|---|---|---|---|
| Kimi K2.8 Preview | $1.00 | $1.00 | $0.25 | $4.00 | - |
Credits settlement: B.AI converts charges at 1 USD = 1,000,000 Credits and deducts Credits from the account balance.
Prices shown in the documentation are B.AI standard reference prices for base billing purposes. B.AI may provide lower actual usage costs through top-up bonuses and account benefits. Specific prices, bonus Credits, and account benefits are subject to the platform display and final billing records.