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Comparison · 2 models · Updated Oct 4, 2026

Kimi K2 Thinking vs Nemotron 3 Ultra 550B A55B

Nemotron 3 Ultra 550B A55B comes out ahead, 62 to 58 on our weighted score, and it is the cheaper option too.

  1. Moonshot AI

    Kimi K2 Thinking

    Released Nov 6, 2025

    58/100
    • ECI146.0
    • Price$0.60 / $2.50
    • Context262K
    Full specs Remove Kimi K2 Thinking
  2. Our pick

    NVIDIA

    Nemotron 3 Ultra 550B A55B

    Released Jun 4, 2026

    62/100
    • ECI146.2
    • Price$0.50 / $2.50
    • Context1M
    Full specs Remove Nemotron 3 Ultra 550B A55B

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Nemotron 3 Ultra 550B A55B is our pick

Nemotron 3 Ultra 550B A55B is the better all-round choice, scoring 62/100 against Kimi K2 Thinking (58). It leads on inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

  • CapabilityNemotron 3 Ultra 550B A55BCapabilities Index (ECI): Nemotron 3 Ultra 550B A55B 146.2 · Kimi K2 Thinking 146.0
  • Lowest priceNemotron 3 Ultra 550B A55BNemotron 3 Ultra 550B A55B $1.00 · Kimi K2 Thinking $1.07 per 1M tokens (3:1 blend)
  • Longest contextNemotron 3 Ultra 550B A55BNemotron 3 Ultra 550B A55B 1,000,000 · Kimi K2 Thinking 262,144 tokens
  • Widest inputsSame inputsKimi K2 Thinking: Text · Nemotron 3 Ultra 550B A55B: Text
  • Self-hostingAll open weightsEvery model here can be downloaded and run on your own hardware
How the score is built
MeasureWeightKimi K2 ThinkingNemotron 3 Ultra 550B A55B
CapabilityCapabilities Index (ECI)50%7373
Price25%4850
Inputs & features15%3545
Context window10%3760
Overall100%58/10062/100
02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Kimi K2 Thinking vs Nemotron 3 Ultra 550B A55B specifications side by side
SpecificationKimi K2 ThinkingMoonshot AINemotron 3 Ultra 550B A55BNVIDIA
Capability
Capabilities Index (ECI)146.0146.2 (best)
ECI rank#72 of 148#70 of 148 (best)
GPQA DiamondGraduate-level science questions84.2%85.4% (best)
OTIS Mock AIME 2024–2025Competition mathematics83.1%86.7% (best)
Price per million tokens
Input$0.60$0.50 (best)
Output$2.50$2.50
Cached input—$0.15
Blended (3:1)$1.07$1.00 (best)
Long-context rateSame rateSame rate
Price sourceMedian of 10 providersOfficial Nvidia API
Limits
Context window262,144 tokens1,000,000 tokens (best)
Max output262,144 tokens (best)128,000 tokens
Inputs and features
TextYesYes
ImagesNoNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYesYes
Tool callingYesYes
Structured outputNoYes
Availability
WeightsOpenOpen
API model ID—nvidia/nemotron-3-ultra-550b-a55b
API providers1021 (best)
ReleasedNov 6, 2025Jun 4, 2026
Knowledge cutoffAug 2024—
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Kimi K2 Thinking$11.00
  • Nemotron 3 Ultra 550B A55B$10.00
04 — Questions

Which should you choose?

Which is better: Kimi K2 Thinking or Nemotron 3 Ultra 550B A55B?

Nemotron 3 Ultra 550B A55B is the better all-round choice, scoring 62/100 against Kimi K2 Thinking (58). It leads on inputs & features and context window. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%.

Which is cheaper, Kimi K2 Thinking or Nemotron 3 Ultra 550B A55B?

Nemotron 3 Ultra 550B A55B is cheaper at $0.50 input / $2.50 output per million tokens (official Nvidia API price). Kimi K2 Thinking costs $0.60 input / $2.50 output per million tokens (median across 10 API providers). At a typical mix of three input tokens to one output token, that is $1.00 per million tokens for Nemotron 3 Ultra 550B A55B versus $1.07 for Kimi K2 Thinking (1.1× as much).

Which scores higher on benchmarks?

Nemotron 3 Ultra 550B A55B scores higher on the Capabilities Index (ECI): Nemotron 3 Ultra 550B A55B 146.2 (#70 of 148) and Kimi K2 Thinking 146.0 (#72 of 148). The confidence ranges of the top two overlap (143.9–148.1 vs 143.4–147.6), so treat the gap as small. On individual benchmarks: GPQA Diamond — Nemotron 3 Ultra 550B A55B 85.4%, Kimi K2 Thinking 84.2%; OTIS Mock AIME 2024–2025 — Nemotron 3 Ultra 550B A55B 86.7%, Kimi K2 Thinking 83.1%.

Which is better for coding?

There are no published SWE-bench Verified results for Kimi K2 Thinking and Nemotron 3 Ultra 550B A55B yet, so there is no like-for-like coding score. On overall capability, Nemotron 3 Ultra 550B A55B leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.

Which has the bigger context window?

Nemotron 3 Ultra 550B A55B has the largest context window at 1,000,000 tokens, against 262,144 for Kimi K2 Thinking. Maximum output per response: Kimi K2 Thinking up to 262,144, Nemotron 3 Ultra 550B A55B up to 128,000 tokens.

Which can read images, PDFs, audio or video?

Kimi K2 Thinking accepts text; Nemotron 3 Ultra 550B A55B accepts text. They handle the same number of input types.

Are any of these open source?

Yes, both publish their weights, so you can self-host them.

Which is newer?

Nemotron 3 Ultra 550B A55B is the newest, released Jun 4, 2026. Kimi K2 Thinking came out Nov 6, 2025. Knowledge cutoff: Kimi K2 Thinking Aug 2024.

How do you decide the winner?

Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.

05 — Keep comparing

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