Skip to main content

NEW You.com Inference Router: Enterprise-grade inference on demand, with an uptime SLA of at least 99.9% and ZDR.

NEW Inference Router: Enterprise-grade inference with ZDR and 99.9% uptime SLA.

Learn More
Moonshot AI

Kimi K3.1 Pro

Moonshot AI’s flagship open-weight multimodal reasoning model, post-trained from Kimi K3 across hundreds of domains with a 1M-token context window.

Released
Oct 23 2026
Modality
Text + Image + Video
Context
1M tokens
Price in / cached input / out
$1.90 / $0.19 / $9.50per 1M tokens

Quickstart

OpenAI-compatible: change the base URL, and the setup is complete.

from openai import OpenAI
import os

client = OpenAI(
    base_url="https://api.you.com/v1",
    api_key=os.environ["YDC_API_KEY"],
)

response = client.chat.completions.create(
    model="kimi-k3.1-pro",
    messages=[{"role": "user", "content": "Summarize this support ticket in two sentences."}],
)

print(response.choices[0].message.content)

Specifications

Technical details, capabilities, pricing, and data handling.

Model info

Input Modality
Text, Image, Video
Output Modality
Text
Context Window
1M
Parameters
2.8T total / 104B active
License
Kimi K3.1 Pro License

Capabilities

Reasoning
Supported
Function calling
Supported
Structured outputs
Supported
Web search grounding
Not supported

Pricing

Input
$1.90
Cached input
$0.19
Output
$9.50

Data handling

Zero data retention
Supported
No training on customer data
Supported
Regions
US

Providers

Access models through multiple providers with automatic routing and built-in failover.

Providers serving Kimi K3.1 Pro
ProviderZDRNo trainingRegion
WaferYesYes
US

When to use Kimi K3.1 Pro

Guidance based on the specifications and benchmarks on this page.

Best for

  • Long-horizon agentic codingScores 65.7% on Terminal-Bench 4.0, just behind Claude Opus 5.5, and 75.5% on DeepSWE v1.1, per Moonshot.
  • Finance and document-heavy researchTops Moonshot's OfficeQA Pro v2 comparison at 64.4 and cuts its hallucination rate on hard factual prompts from 23.4% to 8.3% versus K3.
  • 3D, CAD, and parametric modelingScores 92.7% on BenchCAD with tools and writes Blender and CAD scripts to build and refine 3D assets.
Get API key

Consider alternatives for

  • You need the hardest expert-level reasoningIt scores 39.4 on HLE-Diamond, where Moonshot's own table shows GPT-6 Astra at 65.8 and Claude Opus 5.5 at 60.9.
  • You need low-cost, high-volume inferenceSmaller models such as DeepSeek V4.1 Flash or GPT-OSS 120B fit simple, high-volume workloads at lower cost.
  • You need audio input or outputLike Kimi K3, it handles text, images, and video; audio is not a supported modality.

Benchmarks

Kimi K3.1 Pro results alongside comparable models

Reasoning benchmark scores
BenchmarkKimi K3.1 ProMoonshot AIKimi K3Moonshot AIQwen3.8 MaxAlibabaDeepSeek V4 ProDeepSeekDeepSeek V4.1 FlashDeepSeekBeam 501B-A23BReflection AI
GPQA Diamond94.2%93.5%92.6%90.1%90.9%90.6%
Humanity's Last Exam51.1%43.5%43.6%37.7%36.8%36%
Humanity's Last Exam (with tools)70%56%56.2%48.2%63.9%51.1%

Scores are self-reported by each model’s developer, so settings may vary between models. Sources: Kimi K3.1 Pro (release post), Kimi K3 (Hugging Face), Qwen3.8 Max (Hugging Face), Qwen3.8 Max (release post), DeepSeek V4 Pro (Hugging Face), DeepSeek V4.1 Flash (Hugging Face), Beam 501B-A23B (Hugging Face).

Build with Inference Router

Share a few details and a solutions engineer will reach out to show you what your workloads cost on open-weight models.