Grok 4.5 vs Nemotron 3 Ultra
Grok 4.5 leads Nemotron 3 Ultra on coding, 58.6 to 30.0 on the Vibe Coding Index, and Nemotron 3 Ultra costs 2.5x less per output token ($2.40 vs $6.00 per million). Updated October 22, 2026; 66 benchmarks have a result for both.
Grok 4.5 or Nemotron 3 Ultra: which to pick
Pick Grok 4.5 for coding: it scores 58.6 on the Vibe Coding Index against 30.0 for Nemotron 3 Ultra.
Pick Nemotron 3 Ultra for output tokens 2.5x cheaper ($2.40 vs $6.00 per million) and work measured by LMArena Text: expert or TaxEval (Vals AI), where it leads.
- Shared results
- 66
- Grok 4.5 only
- 58
- Nemotron 3 Ultra only
- 5
- 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
Grok 4.5
Grok 4.5 scores 58.6 against 30.0.
6 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
Grok 4.5
Grok 4.5 leads, 38.8 against 22.9.
Same board, both measured
Agentic work
AA Agentic Index
Grok 4.5
Grok 4.5 leads, 41.2 against 20.1.
Same board, both measured
Reasoning
GPQA Diamond
Grok 4.5
Grok 4.5 leads, 92.9% against 86.1%.
Same board, both measured
Knowledge
MMLU Pro
Grok 4.5
Grok 4.5 leads, 89.2% against 85.8%.
Same board, both measured
Web design
Design Arena: websites
Grok 4.5
Grok 4.5 leads, 1281 against 1145.
Same board, both measured
Long documents
Listed context window
Grok 4.5
Grok 4.5 takes 500K tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Nemotron 3 Ultra
Grok 4.5 $0.0050, Nemotron 3 Ultra $0.0018 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Grok 4.5 has the number, $0.62.
Directional only
At a glance
- Coding index
- Grok 4.5 58.6 from 6 benchmarks, Nemotron 3 Ultra 30.0 from 3 benchmarks.
- Widest category
- Agentic work, 21.8 points apart on average over 5 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Grok 4.5 69.0% against Nemotron 3 Ultra 7.6%, 61.4 points apart on a 0 to 100 scale.
- Output price
- Grok 4.5 $6.00 against Nemotron 3 Ultra $2.40 per million output tokens, 2.5x apart.
- Context window
- Grok 4.5 takes 500K 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 | Grok 4.5 | Bars | Nemotron 3 Ultra | Ties |
|---|---|---|---|---|
| Coding | 11 | 0 | 1 tie | |
| Intelligence | 2 | 0 | ||
| Agentic work | 5 | 0 | ||
| Reasoning | 6 | 1 | ||
| Math | 4 | 0 | ||
| Knowledge | 6 | 3 | ||
| Web design | 8 | 0 | ||
| General | 13 | 5 | 1 tie | |
| All shared boards | 55 | 9 | 2 ties |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index110
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| LiveBench coding | 94.3% | Not measured | Only Grok 4.5 measured |
| LMArena WebDev | 1553 | Not measured | Only Grok 4.5 measured |
| AA Coding Index | 72.4 | 49.3 | Grok 4.5 |
| LiveCodeBench (Vals AI) | 87.3% | 86.0% | Grok 4.5 |
| SWE-bench Verified (Vals AI) | 86.6% | 69.0% | Grok 4.5 |
| Terminal-Bench 4 (Vals AI) | 8.6% | Not measured | Only Grok 4.5 measured |
| Vibe Code Bench (Vals AI) | 69.0% | 7.6% | Grok 4.5 |
| Code migration (Vals AI) | 36.6% | 4.9% | Grok 4.5 |
| ProgramBench (Vals AI) | 0.0% | 0.0% | Tie |
| IOI (Vals AI) | 40.6% | Not measured | Only Grok 4.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 67.8% | 50.9% | Grok 4.5 |
| SkillsBench (Vals AI) | 66.0% | Not measured | Only Grok 4.5 measured |
| CyberBench (Vals AI) | 71.0% | Not measured | Only Grok 4.5 measured |
| SciCode | 55.0% | 40.3% | Grok 4.5 |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 36.4% | Only Nemotron 3 Ultra measured |
| FrontierCode | 42.4% | 13.6% | Grok 4.5 |
| WeirdML | 46.4% | 43.5% | Grok 4.5 |
| ALE-Bench | 1309.3 | Not measured | Only Grok 4.5 measured |
| LMArena Text: coding | 1474 | 1468 | Grok 4.5 |
| LMArena Text: software and IT | 1471 | 1468 | Grok 4.5 |
| LMArena WebDev: React | 1556 | Not measured | Only Grok 4.5 measured |
| LMArena WebDev: HTML | 1567 | Not measured | Only Grok 4.5 measured |
| LMArena WebDev: from an image | 1562 | Not measured | Only Grok 4.5 measured |
| SciCode | 6.5% | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 19 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| AA Intelligence Index | 38.8 | 22.9 | Grok 4.5 |
| Epoch Capabilities Index | 154.1 | 146.0 | Grok 4.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| AA Agentic Index | 41.2 | 20.1 | Grok 4.5 |
| Design Arena: agents building web apps | 1218 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building full-stack apps | 1249 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building mobile apps | 1220 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building Android apps | 1236 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building Godot games | 1229 | Not measured | Only Grok 4.5 measured |
| Design Arena: agents building games | 1236 | Not measured | Only Grok 4.5 measured |
| Design Arena: HTML slides | 1155 | Not measured | Only Grok 4.5 measured |
| Design Arena: PowerPoint slides | 1209 | Not measured | Only Grok 4.5 measured |
| LiveBench research | 85.9% | Not measured | Only Grok 4.5 measured |
| LiveBench browser | 44.0% | Not measured | Only Grok 4.5 measured |
| LiveBench long agentic | 27.9% | Not measured | Only Grok 4.5 measured |
| SREBench (Vals AI) | 0.8% | Not measured | Only Grok 4.5 measured |
| Finance Agent (Vals AI) | 48.4% | 37.7% | Grok 4.5 |
| Tax Agent Bench (Vals AI) | 24.9% | Not measured | Only Grok 4.5 measured |
| Legal Research Bench (Vals AI) | 38.0% | 15.4% | Grok 4.5 |
| Excel Modeling Benchmark (Vals AI) | 52.9% | 31.7% | Grok 4.5 |
| Time Horizon Index (Vals AI) | 6.3% | Not measured | Only Grok 4.5 measured |
| τ²-Bench Telecom | Not measured | 83.3% | Only Nemotron 3 Ultra measured |
| APEX-Agents | 56.2% | 22.7% | Grok 4.5 |
| PostTrainBench | 23.4% | Not measured | Only Grok 4.5 measured |
| Vending-Bench 2 | $3,887 | Not measured | Only Grok 4.5 measured |
| LMArena Search | 1216 | Not measured | Only Grok 4.5 measured |
| MCP Atlas | Not measured | 63.1% | Only Nemotron 3 Ultra measured |
| Neither model has a result on the other 18 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index61
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| GPQA Diamond | 92.9% | 86.1% | Grok 4.5 |
| LiveBench reasoning | 87.2% | Not measured | Only Grok 4.5 measured |
| MMMU Pro (Vals AI) | 61.8% | Not measured | Only Grok 4.5 measured |
| GPQA Diamond (Artificial Analysis run) | 93.1% | 86.7% | Grok 4.5 |
| Humanity's Last Exam (Artificial Analysis run) | 42.7% | 28.4% | Grok 4.5 |
| GPQA Diamond (Epoch AI run) | 93.4% | 85.4% | Grok 4.5 |
| ARC-AGI | 87.2% | Not measured | Only Grok 4.5 measured |
| ARC-AGI-2 | 52.6% | Not measured | Only Grok 4.5 measured |
| SimpleBench | 70.0% | Not measured | Only Grok 4.5 measured |
| Chess puzzles | 35.0% | Not measured | Only Grok 4.5 measured |
| Mystery game puzzles | Not measured | 20.0% | Only Nemotron 3 Ultra measured |
| LMArena Text: hard prompts | 1462 | 1452 | Grok 4.5 |
| LMArena Text: expert | 1465 | 1472 | Nemotron 3 Ultra |
| LMArena Text: hard prompts in English | 1464 | 1453 | Grok 4.5 |
| LMArena Vision: diagrams | 1304 | Not measured | Only Grok 4.5 measured |
| LMArena Vision: homework | 1295 | Not measured | Only Grok 4.5 measured |
| Kagi LLM Benchmark | 83.5% | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 6 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| OTIS Mock AIME | 97.8% | 86.7% | Grok 4.5 |
| FrontierMath, tiers 1 to 3 | 57.2% | Not measured | Only Grok 4.5 measured |
| FrontierMath, tier 4 | 24.4% | Not measured | Only Grok 4.5 measured |
| ProofBench | 31.0% | 2.0% | Grok 4.5 |
| LMArena Text: math | 1460 | 1457 | Grok 4.5 |
| LMArena Text: mathematical work | 1482 | 1461 | Grok 4.5 |
| MathArena | 34.1% | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index63
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| MMLU Pro | 89.2% | 85.8% | Grok 4.5 |
| LegalBench (Vals AI) | 86.0% | 82.1% | Grok 4.5 |
| CorpFin (Vals AI) | 67.4% | 65.5% | Grok 4.5 |
| TaxEval (Vals AI) | 71.7% | 73.1% | Nemotron 3 Ultra |
| MortgageTax (Vals AI) | 61.8% | Not measured | Only Grok 4.5 measured |
| MedCode (Vals AI) | 43.3% | 38.6% | Grok 4.5 |
| SimpleQA Verified | 48.3% | Not measured | Only Grok 4.5 measured |
| LMArena Text: science | 1464 | 1465 | Nemotron 3 Ultra |
| LMArena Text: medicine and healthcare | 1440 | 1456 | Nemotron 3 Ultra |
| LMArena Text: legal and government | 1463 | 1452 | Grok 4.5 |
| LMArena Text: business and finance | 1441 | 1434 | Grok 4.5 |
| FACTS Benchmark Suite | 50.2% | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 8 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| Design Arena: websites | 1281 | 1145 | Grok 4.5 |
| Design Arena: UI components | 1277 | 1135 | Grok 4.5 |
| Design Arena: game dev | 1263 | 1138 | Grok 4.5 |
| Design Arena: data viz | 1266 | 1141 | Grok 4.5 |
| Design Arena: 3D | 1257 | 1131 | Grok 4.5 |
| Design Arena: all code categories | 1275 | 1146 | Grok 4.5 |
| Design Arena: SVG | 1214 | 1069 | Grok 4.5 |
| Design Arena: ASCII art | 1257 | 1100 | Grok 4.5 |
| LiveBench design | 78.1% | Not measured | Only Grok 4.5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index135
| Benchmark | Grok 4.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| LiveBench data analysis | 73.0% | Not measured | Only Grok 4.5 measured |
| SAGE (Vals AI) | 35.0% | Not measured | Only Grok 4.5 measured |
| MedScribe (Vals AI) | 86.9% | Not measured | Only Grok 4.5 measured |
| Vals Multimodal Index | 63.4% | Not measured | Only Grok 4.5 measured |
| IFBench | Not measured | 81.4% | Only Nemotron 3 Ultra measured |
| Long context reasoning (AA-LCR) | 79.3% | 79.3% | Tie |
| DTBench | 96.5% | 90.1% | Grok 4.5 |
| LMCA | 45.2% | 36.9% | Grok 4.5 |
| Surface Evolver Bench | 74.4% | Not measured | Only Grok 4.5 measured |
| Furniture assembly | 22.5% | Not measured | Only Grok 4.5 measured |
| LMArena Text | 1448 | 1445 | Grok 4.5 |
| LMArena Text: instruction following | 1445 | 1418 | Grok 4.5 |
| LMArena Text: creative writing | 1442 | 1399 | Grok 4.5 |
| LMArena Vision | 1287 | Not measured | Only Grok 4.5 measured |
| LMArena Text: English | 1453 | 1455 | Nemotron 3 Ultra |
| LMArena Text: non-English | 1440 | 1427 | Grok 4.5 |
| LMArena Text: Chinese | 1495 | 1497 | Nemotron 3 Ultra |
| LMArena Text: German | 1448 | 1472 | Nemotron 3 Ultra |
| LMArena Text: Japanese | 1430 | Not measured | Only Grok 4.5 measured |
| LMArena Text: Korean | 1406 | 1384 | Grok 4.5 |
| LMArena Text: French | 1457 | 1472 | Nemotron 3 Ultra |
| LMArena Text: Spanish | 1451 | 1455 | Nemotron 3 Ultra |
| LMArena Text: Russian | 1449 | 1417 | Grok 4.5 |
| LMArena Text: Polish | 1432 | 1385 | Grok 4.5 |
| LMArena Text: multi-turn | 1456 | 1411 | Grok 4.5 |
| LMArena Text: longer queries | 1462 | 1437 | Grok 4.5 |
| LMArena Text: writing and language | 1445 | 1406 | Grok 4.5 |
| LMArena Text: entertainment and media | 1434 | 1397 | Grok 4.5 |
| LMArena Vision: English | 1285 | Not measured | Only Grok 4.5 measured |
| LMArena Vision: Chinese | 1345 | Not measured | Only Grok 4.5 measured |
| LMArena Vision: reading text | 1293 | Not measured | Only Grok 4.5 measured |
| LMArena Vision: humor | 1276 | Not measured | Only Grok 4.5 measured |
| LMArena Vision: creative writing | 1293 | Not measured | Only Grok 4.5 measured |
| LMArena Document | 1452 | Not measured | Only Grok 4.5 measured |
| Neither model has a result on the other 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Grok 4.5 | 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 | SpaceXAI Grok 4.5 | NVIDIA Nemotron 3 Ultra |
|---|---|---|
| Maker | xAI | NVIDIA |
| Weights | No public weights listed | Open weights |
| Released | July 8, 2026 | June 4, 2026 |
| Context window | 500K | 262K |
| Input $/Mtok | $2.00 | $0.60 |
| Output $/Mtok | $6.00 | $2.40 |
| Coding index | 58.6 | 30.0 |
| Independent measurements behind it | 6 | 3 |
| Cost per solved task | $0.62 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Grok 4.5 better than Nemotron 3 Ultra for coding?
Pick Grok 4.5 for coding: it scores 58.6 on the Vibe Coding Index against 30.0 for Nemotron 3 Ultra. Pick Nemotron 3 Ultra for output tokens 2.5x cheaper ($2.40 vs $6.00 per million) and work measured by LMArena Text: expert or TaxEval (Vals AI), where it leads.
Which is cheaper, Grok 4.5 or Nemotron 3 Ultra?
Grok 4.5 costs $2.00 per million input tokens and $6.00 per million output tokens; Nemotron 3 Ultra costs $0.60 and $2.40. Cost per solved task is known for Grok 4.5 only.
Which has the bigger context window, Grok 4.5 or Nemotron 3 Ultra?
Grok 4.5, with 500K tokens against 262K.
How many benchmarks is the Grok 4.5 vs Nemotron 3 Ultra comparison based on?
66 benchmarks have a result for both models as of October 22, 2026. Grok 4.5's coding index rests on 6 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.