Nemotron 3 Ultra (free) Open vs 
Claude Fable 5 Paid
Nemotron 3 Ultra (free) vs Claude Fable 5 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.
Claude Fable 5 — full profile ›
Prices & specs refreshed from live data · OpenSourceAI.tech
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
Nemotron 3 Ultra (free) vs Claude Fable 5 specs
| Spec | Nemotron 3 Ultra (free) | Claude Fable 5 |
|---|---|---|
| Maker | NVIDIA | Anthropic |
| Type | Open-weight | Proprietary |
| Context window | 1M tokens | 1M tokens |
| Input price | Free/M · free self-host | $10/M |
| Output price | Free/M · free self-host | $50/M |
| Vision / multimodal | No | Yes |
| Tool / function calling | Yes | Yes |
| Self-hostable | Yes | No (API only) |
| License | NVIDIA Open Model | Proprietary |
Feature comparison
| Capability | Nemotron 3 Ultra (free) | Claude Fable 5 |
|---|---|---|
| Open weights (downloadable) | ✓ | ✗ |
| Self-hostable | ✓ | ✗ |
| Runs fully offline | ✓ | ✗ |
| Vision / multimodal | ✗ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✓ | ✓ |
Benchmarks: Nemotron 3 Ultra (free) vs Claude Fable 5
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
How Nemotron 3 Ultra (free) and Claude Fable 5 score
| Criterion | Nemotron 3 Ultra (free) | Claude Fable 5 |
|---|---|---|
| Cost-efficiency | 5.0 | 2.0 |
| Context window | 5.0 | 5.0 |
| 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 (free) 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...
Claude Fable 5 Paid
Claude Fable 5 is a Mythos-class model from Anthropic, built for autonomous knowledge work and coding. It supports text, image, and file inputs with text output, with reasoning support and...
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 (free) as good as Claude Fable 5?
Nemotron 3 Ultra (free) is open-weight and competitive on many tasks, but Claude Fable 5 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 (free) locally?
Yes. Nemotron 3 Ultra (free) has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Claude Fable 5 is API-only and cannot be self-hosted.
Nemotron 3 Ultra (free) vs Claude Fable 5 — which should I pick in 2026?
Choose Nemotron 3 Ultra (free) 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 Claude Fable 5 if you want frontier capability through a managed API with zero infrastructure to run.
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