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Claude Fable 5 vs NVIDIA Nemotron 3 Ultra 550B A55B

Claude Fable 5 grades higher overall (90.7 against 72.8). NVIDIA Nemotron 3 Ultra 550B A55B costs 95% less for the same work.

Claude Fable 5

by Anthropic · #3 of 67 overall

Coming soon · price at launch
Context
1M
Input / 1M
$10.00
Output / 1M
$50.00

NVIDIA Nemotron 3 Ultra 550B A55B

by NVIDIA · #26 of 67 overall

Coming soon · price at launch
Context
256K
Input / 1M
$0.50
Output / 1M
$2.20

Better overall

Claude Fable 5

Grade 90.7 vs 72.8

Cheaper

NVIDIA Nemotron 3 Ultra 550B A55B

95% less, $0.93 vs $20.00 blended

Larger context

Claude Fable 5

1M vs 256K tokens

SWE-bench Verified

Claude Fable 5

95% vs 70.7%

Head to head

Public benchmarks. Longer is better; each value links to its source.

LMArena TextElo-style rating · LMArena (CC BY 4.0) · Oct 15, 2026
Claude Fable 5Claude Fable 5: 1,503
NVIDIA Nemotron 3 Ultra 550B A55BNVIDIA Nemotron 3 Ultra 550B A55B: 1,426
LMArena WebDevElo-style rating · LMArena (CC BY 4.0) · Oct 13, 2026
Claude Fable 5Claude Fable 5: 1,624
NVIDIA Nemotron 3 Ultra 550B A55BNVIDIA Nemotron 3 Ultra 550B A55B: —
LMArena CodingElo-style rating · LMArena (CC BY 4.0) · Oct 15, 2026
Claude Fable 5Claude Fable 5: 1,551
NVIDIA Nemotron 3 Ultra 550B A55BNVIDIA Nemotron 3 Ultra 550B A55B: 1,474
SWE-bench Verified% of issues resolved · SWE-bench · Jun 9, 2026 · reference
Claude Fable 5Claude Fable 5: 95%v
NVIDIA Nemotron 3 Ultra 550B A55BNVIDIA Nemotron 3 Ultra 550B A55B: 70.7%v
SWE-Bench Pro% of tasks resolved · Scale AI SWE-Bench Pro · Jun 9, 2026 · reference
Claude Fable 5Claude Fable 5: 80%v
NVIDIA Nemotron 3 Ultra 550B A55BNVIDIA Nemotron 3 Ultra 550B A55B: —
Terminal-Bench 2.1% of tasks passed · Terminal-Bench · Jun 9, 2026 · reference
Claude Fable 5Claude Fable 5: 84.3%v
NVIDIA Nemotron 3 Ultra 550B A55BNVIDIA Nemotron 3 Ultra 550B A55B: 56.4%v

Claude Fable 5NVIDIA Nemotron 3 Ultra 550B A55Bv = reported by the model’s maker. — = no public score yet. Arena bars span the range across every model we grade.

What it costs you

Drag to match your monthly usage.

Claude Fable 5$4,000 /month
NVIDIA Nemotron 3 Ultra 550B A55B$188 /month

NVIDIA Nemotron 3 Ultra 550B A55B saves you $3,812 a month at this usage, $45,744 a year.

At a glance

AttributeClaude Fable 5NVIDIA Nemotron 3 Ultra 550B A55B
Made byAnthropicNVIDIA
AvailabilityComing soonComing soon
Overall gradeExcellent · 90.7Excellent · 72.8
Overall rank#3 of 67#26 of 67
Input price$10.00 per 1M$0.50 per 1M
Output price$50.00 per 1M$2.20 per 1M
Context window1,000,000 tokens262,144 tokens
Reasoning levelsYesNo
Reads imagesYesNo
Model IDclaude-fable-5nvidia-nemotron-3-ultra-550b-a55b

Try both with one key

Same endpoint, same key, both hosted in the USA. Change one word to switch models, in Claude Code, Cursor, Cline or your own code.

Get your API key
# Ask either model the same thing
curl https://fullsendai.com/v1/chat/completions \
  -H "Authorization: Bearer $FULLSEND_API_KEY" \
  -d '{"model": "claude-fable-5", "messages": [...]}'

# …then swap one word
  -d '{"model": "nvidia-nemotron-3-ultra-550b-a55b", "messages": [...]}'

Questions

Is Claude Fable 5 or NVIDIA Nemotron 3 Ultra 550B A55B better?

Claude Fable 5 grades 90.7 against 72.8 for NVIDIA Nemotron 3 Ultra 550B A55B, from public benchmarks.

Which is cheaper, Claude Fable 5 or NVIDIA Nemotron 3 Ultra 550B A55B?

NVIDIA Nemotron 3 Ultra 550B A55B: $0.50 in and $2.20 out per million tokens, against $10.00 and $50.00 through FullsendAI.

Which has the larger context window?

Claude Fable 5, with 1,000,000 tokens.

Can I use both with one API key?

Yes, once they launch: both are coming soon, at the prices shown, and both will use the same FullsendAI key.

Compare with others

Model rankingsAll benchmarksCompare other models

Scores: LMArena (CC BY 4.0), SWE-bench, Scale AI SWE-Bench Pro, Terminal-Bench, and model makers’ published results where marked v. Prices are FullsendAI’s, per million tokens. Data as of Oct 28, 2026.