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Model comparison

Kimi K3 vs NVIDIA Nemotron 3 Ultra

Compare Kimi K3 and NVIDIA Nemotron 3 Ultra using the same provider-sourced text & reasoning rubric. No mystery score and no invented benchmark ranking.

Facts checked September 4, 2026

Estimate your cost

Set your usage. Your estimate updates as you type.

Example: 6,000 input tokens for 10 pages, plus a 500-token summary. Page lengths vary; adjust the numbers below.

One run sends your input to the model once and receives an answer. Tokens are pieces of text: input is what you send, output is the answer you receive.

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How this estimate works

Estimates exclude taxes, tools, cache storage/writes, free allowances and custom discounts. Image estimates cover output only, not prompt or reference-image charges. Quality modes differ by model. Unlisted settings are not treated as free.

Estimate your cost
ModelEstimated total (USD)
Kimi K3Moonshot AINo reviewed rate
NVIDIA Nemotron 3 UltraNVIDIANo reviewed rate

Quick take

Kimi K3

Moonshot AI's frontier multimodal model for million-token coding, reasoning, knowledge work, and tool-driven agents.

Best for

  • Large codebase and document work
  • Agents that repeatedly reuse a long context
  • Multimodal reasoning through a direct or gateway API

Watch out for

Moonshot's public terms permit broad service-improvement uses of submitted content. Treat the provider route and enterprise agreement as a core requirement for confidential work.

NVIDIA Nemotron 3 Ultra

NVIDIA's largest Nemotron 3 reasoning model for complex agents, coding, planning, tools, RAG, and million-token analysis.

Best for

  • Complex long-running agents
  • Large-context reasoning and RAG
  • Organizations deploying on NVIDIA infrastructure

Watch out for

Self-hosting Ultra is a substantial hardware project. Size the real context cache, concurrency, precision, and availability requirements before treating open weights as the cheaper route.

Compare the published facts

Kimi K3 vs NVIDIA Nemotron 3 Ultra

Values use each provider's own published units and limits. A blank means the provider did not publish a directly comparable value in the sources reviewed.

Text & reasoningKimi K3NVIDIA Nemotron 3 Ultra
Context windowMaximum combined prompt and working context documented by the provider.1M tokensUp to 1M tokens
Maximum outputProvider-published response limit, where available.Not separately published for the direct APINot separately published
Knowledge cutoffLatest reliable knowledge date explicitly published by the model provider. Search and connected tools can retrieve newer information but do not change the model's built-in cutoff.Not publishedPretraining through Sep 2025; post-training through May 2026
Input priceCurrent standard list price per million input tokens unless noted.$3 / 1M uncached; $0.30 cachedFree prototype or deployment cost
Output priceCurrent standard list price per million output tokens unless noted.$15 / 1MFree prototype or deployment cost
InputsMedia types accepted by the listed model endpoint.Text, imageText
Tools & agentsSelected native tools and agent-building capabilities, not an exhaustive list.Tools, agent workflows, reasoning levels, dynamic tool loading on supported routesTool calling, agents, configurable reasoning budget

How to choose

Compare the job, not the hype.

Start with the job you need to complete, then validate cost, access, and policy details on your exact provider route.

Kimi K3

Moonshot's API privacy and model-use terms allow submitted content to be stored and used to provide, maintain, develop, and improve the service. Obtain appropriate enterprise terms before sending sensitive material.

NVIDIA Nemotron 3 Ultra

Downloaded weights can run in infrastructure the operator controls. NVIDIA's hosted prototype and partner endpoints are governed by their own trial, logging, retention, and deployment terms.

Frequently asked questions

Kimi K3 vs NVIDIA Nemotron 3 Ultra FAQ

What is the main difference between Kimi K3 and NVIDIA Nemotron 3 Ultra?

Kimi K3: Moonshot AI's frontier multimodal model for million-token coding, reasoning, knowledge work, and tool-driven agents. NVIDIA Nemotron 3 Ultra: NVIDIA's largest Nemotron 3 reasoning model for complex agents, coding, planning, tools, RAG, and million-token analysis.

Should I choose Kimi K3 or NVIDIA Nemotron 3 Ultra?

Consider Kimi K3 when your priority is Large codebase and document work. Consider NVIDIA Nemotron 3 Ultra when your priority is Complex long-running agents. Test both with your own data and provider route before committing.

Is this Kimi K3 vs NVIDIA Nemotron 3 Ultra comparison based on Cody benchmarks?

No. This comparison aligns provider-published facts for the Text & reasoning category. It does not claim a universal winner or combine incompatible third-party benchmark scores.