Nemotron 3 Ultra Open vs 
Grok 4.6 Paid
Nemotron 3 Ultra vs Grok 4.6 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.
Prices & specs refreshed from live data · olud.ai
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
$3.13 /M outputNo per-token fees if you self-host
$6 /M outputManaged API (no infra to run)
Nemotron 3 Ultra vs Grok 4.6 specs
| Spec | Nemotron 3 Ultra | Grok 4.6 | Winner |
|---|---|---|---|
| Maker | NVIDIA | xAI | – |
| Type | Open-weight | Proprietary | |
| Context window | 262K tokens | 500K tokens | |
| Input price | $0.63/M · free self-host | $2/M | |
| Output price | $3.13/M · free self-host | $6/M | |
| Vision / multimodal | No | Yes | |
| Tool / function calling | Yes | Yes | = Tie |
| Self-hostable | Yes | No (API only) | |
| License | NVIDIA Open Model | Proprietary |
Price gap & when to choose each
Nemotron 3 Ultra is ~1.9× cheaper than Grok 4.6 on output tokens ($3.13 vs $6 per M tokens).
- You want to self-host or run on your cloud
- You prioritize data privacy & control
- You want the lowest operating costs
- You are building open or reproducible AI
- You want frontier performance through a managed API
- You need the longer 500K context window
- You value reliability & ecosystem
- You don't want to manage infrastructure
Feature comparison
| Capability | Nemotron 3 Ultra | Grok 4.6 |
|---|---|---|
| Open weights (downloadable) | ✓ | ✗ |
| Self-hostable | ✓ | ✗ |
| Runs fully offline | ✓ | ✗ |
| Vision / multimodal | ✗ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✗ | ✗ |
Benchmarks: Nemotron 3 Ultra vs Grok 4.6
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
How Nemotron 3 Ultra and Grok 4.6 score
| Criterion | Nemotron 3 Ultra | Grok 4.6 |
|---|---|---|
| Cost-efficiency | 4.0 | 4.0 |
| Context window | 4.0 | 4.5 |
| Openness | 5.0 | 1.5 |
| Self-hosting | 5.0 | 1.0 |
| Multimodality | 3.5 | 5.0 |
Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.
What each model is
Nemotron 3 Ultra Open
NVIDIA Nemotron 3 Ultra is an open frontier-reasoning and orchestration model from NVIDIA, with 55B active parameters out of 550B total (MoE). Built on a hybrid Transformer-Mamba mixture-of-experts architecture, it...
Grok 4.6 Paid
Grok 4.6 is SpaceXAI's smartest model with frontier performance on coding, knowledge work, and STEM.
Other models in these families
These variants are tracked but not compared here — one page per family keeps the comparison readable.
Frequently asked questions
Is Nemotron 3 Ultra as good as Grok 4.6?
Nemotron 3 Ultra is open-weight and competitive on many tasks, but Grok 4.6 may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.
Can I run Nemotron 3 Ultra locally?
Yes. Nemotron 3 Ultra has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Grok 4.6 is API-only and cannot be self-hosted.
How much cheaper is Nemotron 3 Ultra?
Nemotron 3 Ultra costs $3.13/M output vs $6/M for Grok 4.6 — roughly 2x cheaper via API, and free if you self-host.
Nemotron 3 Ultra vs Grok 4.6 — which should I pick in 2026?
Choose Nemotron 3 Ultra if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Grok 4.6 if you want frontier capability through a managed API with zero infrastructure to run.
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