Kimi
Released October 23, 2026

Kimi K3.1 Pro

Kimi K3.1 Pro is Kimi's 3T-class open-weight flagship with a 1M-token context, built for long-horizon coding, 3D modeling in Blender and CAD, and finance.

Inputs
Text
Image
Video
Outputs
Text

Model Overview

Capabilities, design details, and architectural traits

Kimi K3.1 Pro - 3T-class open-weight model for coding, 3D creation and finance

Kimi K3.1 Pro is the first model of the K3.1 series and Kimi's most capable 3T-class open-weight model, with a 1-million-token context window. It is a post-trained version of Kimi K3, built with large-scale joint RL across hundreds of downstream domains. Its defining focus is long-horizon agentic work: sustained coding sessions, 3D creation, and end-to-end financial workflows.

Defining traitWhat it means
3D creation without MCP connectorsWrites and runs scripts directly in Blender, SolidWorks, Rhino and other professional modeling tools, inferring shape, proportions and spatial relationships from text, sketches or reference images. Strong at parametric modeling such as mechanical parts, architecture and configurable products.
Game engine coding end to endWorks fluently across Unity, Unreal Engine and Godot, combining them with web search and 3D generation to build complete playable experiences, from terrain and boss fights to full project builds.
End-to-end financial workflowsDelivers complete finance work: retrieval over real financial documents, cross-document verification, multi-step numerical reasoning, spreadsheet modeling and auditable investment research.
Always-on thinking with adjustable effortThinking mode is always enabled, with a top-level reasoning_effort setting offering low, high and max (default max).
Highspeed twin variantKimi K3.1 Pro Highspeed delivers the same intelligence with roughly 2-3x faster output.
Open weights with safety controlsFull model weights are released openly, with offensive-security data removed from mid-training and RL to keep attack capability below what the training pipeline would otherwise produce.

Safety-controlled open-weight release

Before publishing the weights, the team traced how offensive-security capability emerged from general training data, then identified and removed cyber-offense-related data from mid-training and RL while keeping general programming tasks intact. The stated principle is to not push the frontier of offensive security in open weights, while letting defensive teams run the model on infrastructure they control.

API surface

The model accepts image and video input, supports strict JSON-schema structured output, and offers a Partial Mode that continues generation from a supplied text prefix. Streaming separates reasoning deltas from final-answer content.

Benchmark Performance

Independent evaluations · Artificial Analysis

55.1%
Intelligence

Accuracy & Capability Details

Humanity's Last Exam52.5%
SciCode - Scientific Coding60.8%
Long Context Reasoning86.3%

Compare Models Side-by-Side

Evaluate specifications, pricing, and independent benchmark indices

Model Details
General Info
ProviderKimiAnthropicAnthropic
Release DateOctober 23, 2026September 22, 2026September 28, 2026
Knowledge Cutoff--Jun 2026
Context & Limits
Context Window
1.0M
Best Context Window
1M1M
Pricing (per 1M tokens)
Input Pricing
$2
Best Input Pricing
$4
$2
Best Input Pricing
Output Pricing
$10
Best Output Pricing
$20
$10
Best Output Pricing
Modalities
Inputs
textimagevideo
textimagefile
textimagefile
Outputs
text
text
text
Benchmarks (0-100)
Intelligence Index55.1
57.6
Best Intelligence Index
56.0
Coding Index---
Agentic Index---
Kimi K3.1 Pro
Claude Opus 5.5
Claude Sonnet 5.5

Humanity's Last Exam

Extremely difficult logical reasoning and knowledge.

53%
Kimi K3.1 Pro
Humanity's Last Exam
Score: 53%
Kimi K3.1 Pro
61%
Claude Opus 5.5
Humanity's Last Exam
Score: 61%
Claude Opus 5.5
55%
Claude Sonnet 5.5
Humanity's Last Exam
Score: 55%
Claude Sonnet 5.5

Long Context Reasoning

Logical reasoning over long context windows.

86%
Kimi K3.1 Pro
Long Context Reasoning
Score: 86%
Kimi K3.1 Pro
85%
Claude Opus 5.5
Long Context Reasoning
Score: 85%
Claude Opus 5.5
83%
Claude Sonnet 5.5
Long Context Reasoning
Score: 83%
Claude Sonnet 5.5

SciCode Benchmark

Scientific coding and mathematical modeling.

61%
Kimi K3.1 Pro
SciCode Benchmark
Score: 61%
Kimi K3.1 Pro
67%
Claude Opus 5.5
SciCode Benchmark
Score: 67%
Claude Opus 5.5
61%
Claude Sonnet 5.5
SciCode Benchmark
Score: 61%
Claude Sonnet 5.5

Independent evaluation data provided by Artificial Analysis. To view the latest benchmarks and full details, visit their official site.

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