Claude Sonnet 5.5 vs Nemotron 3 Ultra
Claude Sonnet 5.5 leads Nemotron 3 Ultra on coding, 87.3 to 30.0 on the Vibe Coding Index, and Nemotron 3 Ultra costs 4.2x less per output token ($2.40 vs $10.00 per million). Updated October 23, 2026; 51 benchmarks have a result for both.
Claude Sonnet 5.5 or Nemotron 3 Ultra: which to pick
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 30.0 for Nemotron 3 Ultra.
Pick Nemotron 3 Ultra for output tokens 4.2x cheaper ($2.40 vs $10.00 per million) and work measured by LMArena Text: Spanish, where it leads.
- Shared results
- 51
- Claude Sonnet 5.5 only
- 48
- Nemotron 3 Ultra only
- 20
- Like-for-like categories
- 8 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
Claude Sonnet 5.5
Claude Sonnet 5.5 scores 87.3 against 30.0.
5 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 56.0 against 22.9.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Nemotron 3 Ultra has a AA Agentic Index result, 20.1.
Directional only
Reasoning
GPQA Diamond
No call
Only Nemotron 3 Ultra has a GPQA Diamond result, 86.1%.
Directional only
Knowledge
MMLU Pro
No call
Only Nemotron 3 Ultra has a MMLU Pro result, 85.8%.
Directional only
Web design
Design Arena: websites
Claude Sonnet 5.5
Claude Sonnet 5.5 leads, 1327 against 1145.
Same board, both measured
General
Vals Index
No call
Only Claude Sonnet 5.5 has a Vals Index result, 70.8%.
Directional only
Long documents
Listed context window
Claude Sonnet 5.5
Claude Sonnet 5.5 takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Nemotron 3 Ultra
Claude Sonnet 5.5 $0.0070, Nemotron 3 Ultra $0.0018 per turn.
List prices
At a glance
- Coding index
- Claude Sonnet 5.5 87.3 from 5 benchmarks, Nemotron 3 Ultra 30.0 from 3 benchmarks.
- Widest category
- Agentic work, 37.5 points apart on average over 4 shared benchmarks.
- Widest single gap
- ProofBench: Claude Sonnet 5.5 100.0% against Nemotron 3 Ultra 2.0%, 98.0 points apart on a 0 to 100 scale.
- Output price
- Claude Sonnet 5.5 $10.00 against Nemotron 3 Ultra $2.40 per million output tokens, 4.2x apart.
- Context window
- Claude Sonnet 5.5 takes 1M tokens, Nemotron 3 Ultra 262K.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Claude Sonnet 5.5 | Bars | Nemotron 3 Ultra | Ties |
|---|---|---|---|---|
| Coding | 8 | 0 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 4 | 0 | ||
| Reasoning | 6 | 0 | ||
| Math | 4 | 0 | ||
| Knowledge | 5 | 0 | ||
| Web design | 6 | 0 | ||
| General | 15 | 1 | ||
| All shared boards | 50 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index80
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| LiveBench coding | 94.7% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev | 1767 | Not measured | Only Claude Sonnet 5.5 measured |
| AA Coding Index | Not measured | 49.3 | Only Nemotron 3 Ultra measured |
| LiveCodeBench (Vals AI) | Not measured | 86.0% | Only Nemotron 3 Ultra measured |
| SWE-bench Verified (Vals AI) | Not measured | 69.0% | Only Nemotron 3 Ultra measured |
| Terminal-Bench 4 (Vals AI) | 64.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Vibe Code Bench (Vals AI) | 92.4% | 7.6% | Claude Sonnet 5.5 |
| Code migration (Vals AI) | 69.8% | 4.9% | Claude Sonnet 5.5 |
| ProgramBench (Vals AI) | 6.5% | 0.0% | Claude Sonnet 5.5 |
| IOI (Vals AI) | 83.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 83.2% | 50.9% | Claude Sonnet 5.5 |
| SWE-bench Multimodal (Vals AI) | 58.3% | Not measured | Only Claude Sonnet 5.5 measured |
| CyberBench (Vals AI) | 59.6% | Not measured | Only Claude Sonnet 5.5 measured |
| SciCode | 61.0% | 40.3% | Claude Sonnet 5.5 |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 36.4% | Only Nemotron 3 Ultra measured |
| FrontierCode | 52.1% | 13.6% | Claude Sonnet 5.5 |
| FrontierSWE | 61.9% | Not measured | Only Claude Sonnet 5.5 measured |
| WeirdML | Not measured | 43.5% | Only Nemotron 3 Ultra measured |
| ALE-Bench | 1819.1 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: coding | 1510 | 1467 | Claude Sonnet 5.5 |
| LMArena Text: software and IT | 1501 | 1468 | Claude Sonnet 5.5 |
| LMArena WebDev: React | 1815 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev: HTML | 1738 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena WebDev: from an image | 1737 | Not measured | Only Claude Sonnet 5.5 measured |
| SciCode | 13.8% | Not measured | Only Claude Sonnet 5.5 measured |
| SWE-Bench Pro V2 | 95.8% | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 17 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| AA Intelligence Index | 56.0 | 22.9 | Claude Sonnet 5.5 |
| Epoch Capabilities Index | 166.2 | 146.0 | Claude Sonnet 5.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 20.1 | Only Nemotron 3 Ultra measured |
| Design Arena: agents building web apps | 1305 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: agents building mobile apps | 1262 | Not measured | Only Claude Sonnet 5.5 measured |
| Design Arena: spreadsheets | 1272 | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench research | 83.6% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench browser | 84.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench long agentic | 78.8% | Not measured | Only Claude Sonnet 5.5 measured |
| SREBench (Vals AI) | 30.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Finance Agent (Vals AI) | 58.1% | 37.7% | Claude Sonnet 5.5 |
| Tax Agent Bench (Vals AI) | 42.0% | Not measured | Only Claude Sonnet 5.5 measured |
| Legal Research Bench (Vals AI) | 48.1% | 15.4% | Claude Sonnet 5.5 |
| Harvey's Legal Agent Benchmark (Vals AI) | 10.4% | Not measured | Only Claude Sonnet 5.5 measured |
| Excel Modeling Benchmark (Vals AI) | 75.7% | 31.7% | Claude Sonnet 5.5 |
| BioMysteryBench (Vals AI) | 81.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Terminal-Bench-Science (Vals AI) | 47.1% | Not measured | Only Claude Sonnet 5.5 measured |
| Vals Science Index | 59.1% | Not measured | Only Claude Sonnet 5.5 measured |
| τ²-Bench Telecom | Not measured | 83.3% | Only Nemotron 3 Ultra measured |
| APEX-Agents | 75.5% | 22.7% | Claude Sonnet 5.5 |
| SpireClimb | 1.3% | Not measured | Only Claude Sonnet 5.5 measured |
| Vending-Bench 2 | $11,165 | Not measured | Only Claude Sonnet 5.5 measured |
| MCP Atlas | Not measured | 63.1% | Only Nemotron 3 Ultra measured |
| Neither model has a result on the other 21 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 86.1% | Only Nemotron 3 Ultra measured |
| LiveBench reasoning | 91.6% | Not measured | Only Claude Sonnet 5.5 measured |
| MysteryMechanism (Vals AI) | 49.1% | Not measured | Only Claude Sonnet 5.5 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 86.7% | Only Nemotron 3 Ultra measured |
| Humanity's Last Exam (Artificial Analysis run) | 55.0% | 28.4% | Claude Sonnet 5.5 |
| GPQA Diamond (Epoch AI run) | 95.6% | 85.4% | Claude Sonnet 5.5 |
| Chess puzzles | 59.0% | Not measured | Only Claude Sonnet 5.5 measured |
| Mystery game puzzles | 65.0% | 20.0% | Claude Sonnet 5.5 |
| LMArena Text: hard prompts | 1493 | 1452 | Claude Sonnet 5.5 |
| LMArena Text: expert | 1530 | 1472 | Claude Sonnet 5.5 |
| LMArena Text: hard prompts in English | 1502 | 1453 | Claude Sonnet 5.5 |
| LMArena Vision: diagrams | 1329 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: homework | 1331 | Not measured | Only Claude Sonnet 5.5 measured |
| Humanity's Last Exam (Scale run) | 37.5% | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 9 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | 86.7% | Claude Sonnet 5.5 |
| FrontierMath, tiers 1 to 3 | 88.8% | Not measured | Only Claude Sonnet 5.5 measured |
| FrontierMath, tier 4 | 80.5% | Not measured | Only Claude Sonnet 5.5 measured |
| ProofBench | 100.0% | 2.0% | Claude Sonnet 5.5 |
| LMArena Text: math | 1498 | 1457 | Claude Sonnet 5.5 |
| LMArena Text: mathematical work | 1511 | 1462 | Claude Sonnet 5.5 |
| Neither model has a result on the other 8 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 85.8% | Only Nemotron 3 Ultra measured |
| LegalBench (Vals AI) | Not measured | 82.1% | Only Nemotron 3 Ultra measured |
| CorpFin (Vals AI) | Not measured | 65.5% | Only Nemotron 3 Ultra measured |
| TaxEval (Vals AI) | Not measured | 73.1% | Only Nemotron 3 Ultra measured |
| MedCode (Vals AI) | 52.9% | 38.6% | Claude Sonnet 5.5 |
| SimpleQA Verified | 46.5% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: science | 1486 | 1465 | Claude Sonnet 5.5 |
| LMArena Text: medicine and healthcare | 1467 | 1455 | Claude Sonnet 5.5 |
| LMArena Text: legal and government | 1480 | 1453 | Claude Sonnet 5.5 |
| LMArena Text: business and finance | 1468 | 1435 | Claude Sonnet 5.5 |
| Neither model has a result on the other 10 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index60
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| Design Arena: websites | 1327 | 1145 | Claude Sonnet 5.5 |
| Design Arena: UI components | 1369 | 1135 | Claude Sonnet 5.5 |
| Design Arena: game dev | 1470 | 1138 | Claude Sonnet 5.5 |
| Design Arena: data viz | 1382 | 1142 | Claude Sonnet 5.5 |
| Design Arena: 3D | 1400 | 1132 | Claude Sonnet 5.5 |
| Design Arena: all code categories | 1357 | 1146 | Claude Sonnet 5.5 |
| Design Arena: SVG | Not measured | 1069 | Only Nemotron 3 Ultra measured |
| Design Arena: ASCII art | Not measured | 1100 | Only Nemotron 3 Ultra measured |
| LiveBench design | 85.0% | Not measured | Only Claude Sonnet 5.5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index151
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| Vals Index | 70.8% | Not measured | Only Claude Sonnet 5.5 measured |
| LiveBench data analysis | 59.5% | Not measured | Only Claude Sonnet 5.5 measured |
| Public Benefits Bench (Vals AI) | 67.2% | Not measured | Only Claude Sonnet 5.5 measured |
| SAGE (Vals AI) | 51.8% | Not measured | Only Claude Sonnet 5.5 measured |
| MedScribe (Vals AI) | 91.1% | Not measured | Only Claude Sonnet 5.5 measured |
| IFBench | Not measured | 81.4% | Only Nemotron 3 Ultra measured |
| Long context reasoning (AA-LCR) | 82.7% | 79.3% | Claude Sonnet 5.5 |
| DTBench | 97.3% | 90.1% | Claude Sonnet 5.5 |
| LMCA | 68.3% | 36.9% | Claude Sonnet 5.5 |
| Furniture assembly | 75.0% | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text | 1473 | 1445 | Claude Sonnet 5.5 |
| LMArena Text: instruction following | 1491 | 1418 | Claude Sonnet 5.5 |
| LMArena Text: creative writing | 1468 | 1398 | Claude Sonnet 5.5 |
| LMArena Vision | 1287 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: English | 1486 | 1454 | Claude Sonnet 5.5 |
| LMArena Text: non-English | 1456 | 1427 | Claude Sonnet 5.5 |
| LMArena Text: Chinese | 1535 | 1498 | Claude Sonnet 5.5 |
| LMArena Text: German | Not measured | 1474 | Only Nemotron 3 Ultra measured |
| LMArena Text: Japanese | 1460 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Text: Korean | Not measured | 1385 | Only Nemotron 3 Ultra measured |
| LMArena Text: French | 1495 | 1473 | Claude Sonnet 5.5 |
| LMArena Text: Spanish | 1446 | 1454 | Nemotron 3 Ultra |
| LMArena Text: Russian | 1458 | 1417 | Claude Sonnet 5.5 |
| LMArena Text: Polish | Not measured | 1385 | Only Nemotron 3 Ultra measured |
| LMArena Text: multi-turn | 1465 | 1411 | Claude Sonnet 5.5 |
| LMArena Text: longer queries | 1495 | 1437 | Claude Sonnet 5.5 |
| LMArena Text: writing and language | 1476 | 1405 | Claude Sonnet 5.5 |
| LMArena Text: entertainment and media | 1462 | 1397 | Claude Sonnet 5.5 |
| LMArena Vision: English | 1289 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: reading text | 1297 | Not measured | Only Claude Sonnet 5.5 measured |
| LMArena Vision: creative writing | 1242 | Not measured | Only Claude Sonnet 5.5 measured |
| Neither model has a result on the other 17 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Sonnet 5.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Nemotron 3 Ultra costs less
Repository review
50K input + 3K output tokens
Nemotron 3 Ultra costs less
Agent loop
200K input + 10K output tokens
Nemotron 3 Ultra costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | Anthropic Claude Sonnet 5.5 | NVIDIA Nemotron 3 Ultra |
|---|---|---|
| Maker | Anthropic | NVIDIA |
| Weights | No public weights listed | Open weights |
| Released | September 28, 2026 | June 4, 2026 |
| Context window | 1M | 262K |
| Input $/Mtok | $2.00 | $0.60 |
| Output $/Mtok | $10.00 | $2.40 |
| Coding index | 87.3 | 30.0 |
| Independent measurements behind it | 5 | 3 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Sonnet 5.5 better than Nemotron 3 Ultra for coding?
Pick Claude Sonnet 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 30.0 for Nemotron 3 Ultra. Pick Nemotron 3 Ultra for output tokens 4.2x cheaper ($2.40 vs $10.00 per million) and work measured by LMArena Text: Spanish, where it leads.
Which is cheaper, Claude Sonnet 5.5 or Nemotron 3 Ultra?
Claude Sonnet 5.5 costs $2.00 per million input tokens and $10.00 per million output tokens; Nemotron 3 Ultra costs $0.60 and $2.40. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Sonnet 5.5 or Nemotron 3 Ultra?
Claude Sonnet 5.5, with 1M tokens against 262K.
How many benchmarks is the Claude Sonnet 5.5 vs Nemotron 3 Ultra comparison based on?
51 benchmarks have a result for both models as of October 23, 2026. Claude Sonnet 5.5's coding index rests on 5 independent benchmarks and Nemotron 3 Ultra's on 3. Where only one model has a result, the page says so instead of naming a winner.