Model comparison
Claude Fable 5 vs NVIDIA Nemotron 3 Ultra
Anthropic against NVIDIA, compared on context, price, and verified benchmark results.
Catalog record checked September 3, 2026Individual provider fields may changeEvidence confidence: High — see receipts below
Anthropic
Claude Fable 5
Frontier
NVIDIA
NVIDIA Nemotron 3 Ultra
Frontier · Open weights
| Specification | Claude Fable 5 | NVIDIA Nemotron 3 Ultra |
|---|---|---|
| Provider | Anthropic | NVIDIA |
| Tier | Frontier | Frontier |
| Context window | 1M | 1M |
| Max output | 128K | Not verifiedUnverified |
| Input / 1M tokens | $10 | Winner: $0.50 |
| Output / 1M tokens | $50 | Winner: $2.20 |
| Weights | Closed | Open |
| Parameters | Not disclosedUnverified | 550B total / 55B active (MoE) |
| Reasoning levels | adaptive | low, high, max |
| Modalities | text, image | text |
| API model id | claude-fable-5 | nemotron-3-ultra-550b-a55b |
| Released | June 9, 2026 | June 4, 2026 |
| Artificial Analysis Intelligence Index (2026-08-14) | Winner: 62 | 54 |
Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.
Benchmark receipts
- 2026-08-14: Artificial AnalysisComposite index blending reasoning, knowledge, and coding evals into one 0–100 score. Comparability: directly comparable — AA occasionally rebaselines the index scale between snapshots — a score captured on one date is only comparable to same-snapshot scores (check measuredAt).
Pricing tiers: Claude Fable 5: Standard $10/$50 per MTok; cache reads 10% of base input. Sibling Claude Mythos 5 is invite-only cyber-defense. Access briefly suspended 2026-06-12, redeployed 2026-07-01. · NVIDIA Nemotron 3 Ultra: Open weights (weights + data + recipes); $0.50/$2.20 per MTok is the third-party hosted rate (OpenRouter). 550B/55B MoE.
Claude Fable 5
Claude Fable 5 is Anthropic's next-generation intelligence model for long-running agents, topped LiveBench until the 5.1 refresh.
Best for
- Long-running agents
- Frontier reasoning
- Enterprise work
Watch out
Most expensive Anthropic tier at $10/$50; verify the cost is justified by the task.
NVIDIA Nemotron 3 Ultra
Nemotron 3 Ultra is NVIDIA's open-weight (550B/55B) frontier MoE with a 1M-token context.
Best for
- Open-weight frontier
- Self-hosting on NVIDIA GPUs
- Reasoning
Watch out
Top US open-weight until Thinking Machines Inkling; verify hosted pricing.
When the cheaper one wins
NVIDIA Nemotron 3 Ultra is cheaper on output at $2.20 per million tokens against $50 for Claude Fable 5 — about 23×. Use the cheaper tier for classification, extraction, summarisation, and any task where the expensive model’s extra score does not change the accepted output. The expensive one only pays if your hardest task actually fails on the cheap tier. These are standard-tier API rates, excluding batch and cache discounts.
Run the model pickerEvidence confidence: High
How strong and complete the evidence behind this comparison is — not a prediction of which model is better.
- Pricing verified on both sides — Input and output rates are verified for both models.
- 3/5 core specs verified on both sides — Not published for at least one side: max output, parameter count.
- 1 shared named benchmark with differing scores — Measured on: Artificial Analysis Intelligence Index.
- Verified within the last 90 days — Newest catalog check was 8 days ago.
- Both models carry source citations — Each side has at least two catalog sources on record.
Source receipts
Each catalog figure was checked against the provider or an independent second source on the date shown.
- Claude Fable 5: Anthropic — Claude Fable 5 (accessed 2026-08-29)
- Claude Fable 5: Anthropic news — Claude Fable 5 (accessed 2026-08-29)
- NVIDIA Nemotron 3 Ultra: NVIDIA — Nemotron (accessed 2026-08-29)
- NVIDIA Nemotron 3 Ultra: NVIDIA Nemotron 3 Ultra (accessed 2026-08-29)
Related comparisons
- Claude Fable 5.1 vs NVIDIA Nemotron 3 Ultra
- Claude Fable 5 vs Claude Fable 5.1
- Claude Fable 5 vs Claude Haiku 4.5
- Claude Fable 5 vs Claude Mythos 5.1
- Claude Fable 5 vs Claude Opus 5
- Claude Fable 5 vs Claude Sonnet 5
Diving deeper on one model? Claude Fable 5 · NVIDIA Nemotron 3 Ultra
Common questions
Claude Fable 5 vs NVIDIA Nemotron 3 Ultra
Answered from the verified figures on this page rather than general guidance.
Is Claude Fable 5 or NVIDIA Nemotron 3 Ultra cheaper for input?
NVIDIA Nemotron 3 Ultra is cheaper at $0.50 per million input tokens, against $10 for Claude Fable 5 — roughly 20× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Claude Fable 5 has tiered pricing: Standard $10/$50 per MTok; cache reads 10% of base input. Sibling Claude Mythos 5 is invite-only cyber-defense. Access briefly suspended 2026-06-12, redeployed 2026-07-01. NVIDIA Nemotron 3 Ultra has tiered pricing: Open weights (weights + data + recipes); $0.50/$2.20 per MTok is the third-party hosted rate (OpenRouter). 550B/55B MoE.
Is Claude Fable 5 or NVIDIA Nemotron 3 Ultra cheaper for output?
NVIDIA Nemotron 3 Ultra is cheaper at $2.20 per million output tokens, against $50 for Claude Fable 5 — roughly 23× the price. Output tokens usually dominate a real bill, so weigh the output rate more heavily than the input rate. These are base rates; Claude Fable 5 has tiered pricing: Standard $10/$50 per MTok; cache reads 10% of base input. Sibling Claude Mythos 5 is invite-only cyber-defense. Access briefly suspended 2026-06-12, redeployed 2026-07-01. NVIDIA Nemotron 3 Ultra has tiered pricing: Open weights (weights + data + recipes); $0.50/$2.20 per MTok is the third-party hosted rate (OpenRouter). 550B/55B MoE.
Which has the larger context window, Claude Fable 5 or NVIDIA Nemotron 3 Ultra?
Both accept about 1M tokens of context, so document length will not decide between them.
Do Claude Fable 5 and NVIDIA Nemotron 3 Ultra support the same reasoning levels?
Claude Fable 5 exposes adaptive, while NVIDIA Nemotron 3 Ultra exposes low, high, max.
Should I use Claude Fable 5 or NVIDIA Nemotron 3 Ultra?
Both sit in the frontier tier, so the choice usually comes down to price and context rather than capability. Claude Fable 5 suits long-running agents; NVIDIA Nemotron 3 Ultra suits open-weight frontier.
Can I self-host Claude Fable 5 or NVIDIA Nemotron 3 Ultra?
NVIDIA Nemotron 3 Ultra publishes open weights, but self-hosting and third-party provider access depend on the licence, hardware, serving support, and availability. Claude Fable 5 is a closed model whose supported access paths are controlled by its provider.
Next step
Choosing between them
The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.
- Input price: NVIDIA Nemotron 3 Ultra costs $0.50 per 1M tokens versus $10 for Claude Fable 5 — a 20x difference at the headline tier.
- Deployment: NVIDIA Nemotron 3 Ultra publishes weights you can self-host; the other is API-only.
Choosing a harness rather than a model — Cursor, Copilot, Claude Code, Windsurf, or Lovable? Compare agentic harnesses · Latest releases.