Kimi K2.8 Preview vs Nemotron 3 Ultra (550B A55B)
Comparing Kimi K2.8 Preview and Nemotron 3 Ultra (550B A55B) across benchmarks, pricing, and capabilities.
Moonshot AI · NVIDIA · Updated for 2026
Which is better?
Kimi K2.8 Preview and Nemotron 3 Ultra (550B A55B) trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
Kimi K2.8 Preview also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Kimi K2.8 Preview
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Sep 2026
Choose Nemotron 3 Ultra (550B A55B)
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Individual benchmarks
0 reported for Kimi K2.8 Preview · 26 for Nemotron 3 Ultra (550B A55B)
Kimi K2.8 Preview and Nemotron 3 Ultra (550B A55B)don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Context Window
Maximum input and output token capacity
Kimi K2.8 Preview accepts 1,048,576 input tokens compared to Nemotron 3 Ultra (550B A55B)'s 262,144 tokens. Only Nemotron 3 Ultra (550B A55B) specifies output context (262,144 tokens).
Input capabilities
Documented input modalities across available providers
Kimi K2.8 Preview supports multimodal inputs, whereas Nemotron 3 Ultra (550B A55B) does not.
Kimi K2.8 Preview can handle both text and other forms of data like images, making it suitable for multimodal applications.
Kimi K2.8 Preview
Nemotron 3 Ultra (550B A55B)
License
Usage and distribution terms
Kimi K2.8 Preview is licensed under a proprietary license, while Nemotron 3 Ultra (550B A55B) uses OpenMDW License v1.1.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
OpenMDW License v1.1
Open weights
Release Timeline
When each model was launched
Kimi K2.8 Preview was released on 2026-09-11, while Nemotron 3 Ultra (550B A55B) was released on 2026-06-04.
Kimi K2.8 Preview is 3 months newer than Nemotron 3 Ultra (550B A55B).
Sep 11, 2026
1 weeks ago
3mo newerJun 4, 2026
3 months ago
Knowledge Cutoff
When training data ends
Nemotron 3 Ultra (550B A55B) has a documented knowledge cutoff of 2025-09-30, while Kimi K2.8 Preview's cutoff date is not specified.
We can confirm Nemotron 3 Ultra (550B A55B)'s training data extends to 2025-09-30, but cannot make a direct comparison without Kimi K2.8 Preview's cutoff date.
—
Sep 2025
Provider Availability
Kimi K2.8 Preview is available from Moonshot AI. Nemotron 3 Ultra (550B A55B) is available from DeepInfra.
Kimi K2.8 Preview
Nemotron 3 Ultra (550B A55B)
Outputs Comparison
Judge for yourself.
Run your own prompts against Kimi K2.8 Preview and Nemotron 3 Ultra (550B A55B) side-by-side, then vote on the output you prefer.
FAQ
Common questions about Kimi K2.8 Preview vs Nemotron 3 Ultra (550B A55B).