Kimi K2.5 vs Nemotron 3 Ultra
Kimi K2.5 leads Nemotron 3 Ultra on coding, 38.6 to 30.0 on the Vibe Coding Index, at about the same output price ($2.85 vs $2.40 per million). Updated October 22, 2026; 59 benchmarks have a result for both.
Kimi K2.5 or Nemotron 3 Ultra: which to pick
Pick Kimi K2.5 for coding: it scores 38.6 on the Vibe Coding Index against 30.0 for Nemotron 3 Ultra.
Pick Nemotron 3 Ultra for output tokens 1.2x cheaper ($2.40 vs $2.85 per million) and work measured by AA Coding Index or LiveCodeBench (Vals AI), where it leads.
- Shared results
- 59
- Kimi K2.5 only
- 48
- Nemotron 3 Ultra only
- 12
- 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
Kimi K2.5
Kimi K2.5 scores 38.6 against 30.0.
3 benchmarks behind each score
Intelligence
AA Intelligence Index
Kimi K2.5
Kimi K2.5 leads, 23.5 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
Nemotron 3 Ultra
Nemotron 3 Ultra leads, 86.1% against 84.1%.
Same board, both measured
Math
AIME
No call
Only Kimi K2.5 has a AIME result, 95.6%.
Directional only
Knowledge
MMLU Pro
Kimi K2.5
Kimi K2.5 leads, 85.9% against 85.8%.
Same board, both measured
Web design
Design Arena: websites
Kimi K2.5
Kimi K2.5 leads, 1248 against 1145.
Same board, both measured
Long documents
Listed context window
No call
Both take 262K tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Nemotron 3 Ultra
Kimi K2.5 $0.0020, Nemotron 3 Ultra $0.0018 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Kimi K2.5 has the number, $0.24.
Directional only
At a glance
- Coding index
- Kimi K2.5 38.6 from 3 benchmarks, Nemotron 3 Ultra 30.0 from 3 benchmarks.
- Widest category
- Web design, 10.2 points apart on average over 8 shared benchmarks.
- Widest single gap
- Design Arena: websites: Kimi K2.5 1248 against Nemotron 3 Ultra 1145, 12.9 points apart on a 0 to 100 scale.
- Output price
- Kimi K2.5 $2.85 against Nemotron 3 Ultra $2.40 per million output tokens, 1.2x apart.
- Context window
- Both take 262K tokens.
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 | Kimi K2.5 | Bars | Nemotron 3 Ultra | Ties |
|---|---|---|---|---|
| Coding | 6 | 4 | ||
| Intelligence | 2 | 0 | ||
| Agentic work | 3 | 2 | ||
| Reasoning | 4 | 2 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 4 | ||
| Web design | 8 | 0 | ||
| General | 11 | 7 | ||
| All shared boards | 40 | 19 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index64
| Benchmark | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| SWE-bench Verified | 70.8% | Not measured | Only Kimi K2.5 measured |
| SWE-bench Multilingual | 67.3% | Not measured | Only Kimi K2.5 measured |
| LMArena WebDev | 1437 | Not measured | Only Kimi K2.5 measured |
| AA Coding Index | 46.8 | 49.3 | Nemotron 3 Ultra |
| LiveCodeBench (Vals AI) | 83.9% | 86.0% | Nemotron 3 Ultra |
| SWE-bench Verified (Vals AI) | 70.0% | 69.0% | Kimi K2.5 |
| Vibe Code Bench (Vals AI) | 17.5% | 7.6% | Kimi K2.5 |
| Code migration (Vals AI) | 7.0% | 4.9% | Kimi K2.5 |
| ProgramBench (Vals AI) | Not measured | 0.0% | Only Nemotron 3 Ultra measured |
| Terminal-Bench 2.1 (Vals AI) | 42.0% | 50.9% | Nemotron 3 Ultra |
| SciCode | Not measured | 40.3% | Only Nemotron 3 Ultra measured |
| Terminal-Bench Hard (Artificial Analysis run) | 34.8% | 36.4% | Nemotron 3 Ultra |
| Terminal-Bench | 43.2% | Not measured | Only Kimi K2.5 measured |
| FrontierCode | Not measured | 13.6% | Only Nemotron 3 Ultra measured |
| WeirdML | 45.6% | 43.5% | Kimi K2.5 |
| ALE-Bench | 821.6 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: coding | 1483 | 1468 | Kimi K2.5 |
| LMArena Text: software and IT | 1471 | 1468 | Kimi K2.5 |
| LMArena WebDev: React | 1429 | Not measured | Only Kimi K2.5 measured |
| LMArena WebDev: HTML | 1426 | Not measured | Only Kimi K2.5 measured |
| LMArena WebDev: from an image | 1439 | Not measured | Only Kimi K2.5 measured |
| SWE Atlas: Codebase QnA | 13.1% | Not measured | Only Kimi K2.5 measured |
| SWE Atlas: Refactoring | 20.9% | Not measured | Only Kimi K2.5 measured |
| SWE Atlas: Test Writing | 25.8% | Not measured | Only Kimi K2.5 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 | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| AA Intelligence Index | 23.5 | 22.9 | Kimi K2.5 |
| Epoch Capabilities Index | 148.1 | 146.0 | Kimi K2.5 |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index32
| Benchmark | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 20.1 | Only Nemotron 3 Ultra measured |
| Design Arena: agents building web apps | 1136 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building full-stack apps | 1114 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building mobile apps | 1147 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building Android apps | 1118 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building Godot games | 1219 | Not measured | Only Kimi K2.5 measured |
| Finance Agent (Vals AI) | 35.8% | 37.7% | Nemotron 3 Ultra |
| Legal Research Bench (Vals AI) | 15.9% | 15.4% | Kimi K2.5 |
| Excel Modeling Benchmark (Vals AI) | 28.5% | 31.7% | Nemotron 3 Ultra |
| τ²-Bench Telecom | 95.9% | 83.3% | Kimi K2.5 |
| APEX-Agents | Not measured | 22.7% | Only Nemotron 3 Ultra measured |
| OSWorld | 63.3% | Not measured | Only Kimi K2.5 measured |
| Vending-Bench 2 | $1,198 | Not measured | Only Kimi K2.5 measured |
| MCP Atlas | 64.4% | 63.1% | Kimi K2.5 |
| Neither model has a result on the other 28 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index42
| Benchmark | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| GPQA Diamond | 84.1% | 86.1% | Nemotron 3 Ultra |
| MMMU Pro (Vals AI) | 84.3% | Not measured | Only Kimi K2.5 measured |
| GPQA Diamond (Artificial Analysis run) | 87.9% | 86.7% | Kimi K2.5 |
| Humanity's Last Exam (Artificial Analysis run) | 30.7% | 28.4% | Kimi K2.5 |
| GPQA Diamond (Epoch AI run) | Not measured | 85.4% | Only Nemotron 3 Ultra measured |
| ARC-AGI | 65.3% | Not measured | Only Kimi K2.5 measured |
| ARC-AGI-2 | 11.8% | Not measured | Only Kimi K2.5 measured |
| SimpleBench | 46.8% | Not measured | Only Kimi K2.5 measured |
| Mystery game puzzles | Not measured | 20.0% | Only Nemotron 3 Ultra measured |
| LMArena Text: hard prompts | 1453 | 1452 | Kimi K2.5 |
| LMArena Text: expert | 1466 | 1472 | Nemotron 3 Ultra |
| LMArena Text: hard prompts in English | 1460 | 1453 | Kimi K2.5 |
| LMArena Vision: diagrams | 1282 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: homework | 1297 | Not measured | Only Kimi K2.5 measured |
| Kagi LLM Benchmark | 78.5% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 8 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| AIME | 95.6% | Not measured | Only Kimi K2.5 measured |
| OTIS Mock AIME | Not measured | 86.7% | Only Nemotron 3 Ultra measured |
| ProofBench | Not measured | 2.0% | Only Nemotron 3 Ultra measured |
| LMArena Text: math | 1470 | 1457 | Kimi K2.5 |
| LMArena Text: mathematical work | 1473 | 1461 | Kimi K2.5 |
| MathArena | 17.9% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 8 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index44
| Benchmark | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| MMLU Pro | 85.9% | 85.8% | Kimi K2.5 |
| LegalBench (Vals AI) | Not measured | 82.1% | Only Nemotron 3 Ultra measured |
| CaseLaw (Vals AI) | 58.7% | Not measured | Only Kimi K2.5 measured |
| CorpFin (Vals AI) | 68.3% | 65.5% | Kimi K2.5 |
| TaxEval (Vals AI) | 74.2% | 73.1% | Kimi K2.5 |
| MortgageTax (Vals AI) | 66.5% | Not measured | Only Kimi K2.5 measured |
| MedQA (Vals AI) | 94.4% | Not measured | Only Kimi K2.5 measured |
| MedCode (Vals AI) | 39.3% | 38.6% | Kimi K2.5 |
| SimpleQA Verified | 34.3% | Not measured | Only Kimi K2.5 measured |
| LMArena Text: science | 1459 | 1465 | Nemotron 3 Ultra |
| LMArena Text: medicine and healthcare | 1448 | 1456 | Nemotron 3 Ultra |
| LMArena Text: legal and government | 1441 | 1452 | Nemotron 3 Ultra |
| LMArena Text: business and finance | 1427 | 1434 | Nemotron 3 Ultra |
| PRBench Finance | 46.5% | Not measured | Only Kimi K2.5 measured |
| PRBench Legal | 43.8% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 5 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index80
| Benchmark | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| Design Arena: websites | 1248 | 1145 | Kimi K2.5 |
| Design Arena: UI components | 1234 | 1135 | Kimi K2.5 |
| Design Arena: game dev | 1206 | 1138 | Kimi K2.5 |
| Design Arena: data viz | 1219 | 1141 | Kimi K2.5 |
| Design Arena: 3D | 1204 | 1131 | Kimi K2.5 |
| Design Arena: all code categories | 1236 | 1146 | Kimi K2.5 |
| Design Arena: SVG | 1148 | 1069 | Kimi K2.5 |
| Design Arena: ASCII art | 1165 | 1100 | Kimi K2.5 |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index117
| Benchmark | Kimi K2.5 | Nemotron 3 Ultra | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 49.9% | Not measured | Only Kimi K2.5 measured |
| MedScribe (Vals AI) | 76.4% | Not measured | Only Kimi K2.5 measured |
| IFBench | 70.2% | 81.4% | Nemotron 3 Ultra |
| Long context reasoning (AA-LCR) | 78.0% | 79.3% | Nemotron 3 Ultra |
| DTBench | Not measured | 90.1% | Only Nemotron 3 Ultra measured |
| LMCA | Not measured | 36.9% | Only Nemotron 3 Ultra measured |
| Fiction.LiveBench | 86.1% | Not measured | Only Kimi K2.5 measured |
| CL-bench | 19.3% | Not measured | Only Kimi K2.5 measured |
| CL-bench Life | 13.2% | Not measured | Only Kimi K2.5 measured |
| LMArena Text | 1445 | 1445 | Kimi K2.5 |
| LMArena Text: instruction following | 1431 | 1418 | Kimi K2.5 |
| LMArena Text: creative writing | 1422 | 1399 | Kimi K2.5 |
| LMArena Vision | 1269 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: English | 1453 | 1455 | Nemotron 3 Ultra |
| LMArena Text: non-English | 1433 | 1427 | Kimi K2.5 |
| LMArena Text: Chinese | 1494 | 1497 | Nemotron 3 Ultra |
| LMArena Text: German | 1441 | 1472 | Nemotron 3 Ultra |
| LMArena Text: Japanese | 1423 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: Korean | 1412 | 1384 | Kimi K2.5 |
| LMArena Text: French | 1454 | 1472 | Nemotron 3 Ultra |
| LMArena Text: Spanish | 1450 | 1455 | Nemotron 3 Ultra |
| LMArena Text: Russian | 1435 | 1417 | Kimi K2.5 |
| LMArena Text: Polish | 1445 | 1385 | Kimi K2.5 |
| LMArena Text: multi-turn | 1444 | 1411 | Kimi K2.5 |
| LMArena Text: longer queries | 1445 | 1437 | Kimi K2.5 |
| LMArena Text: writing and language | 1425 | 1406 | Kimi K2.5 |
| LMArena Text: entertainment and media | 1417 | 1397 | Kimi K2.5 |
| LMArena Vision: English | 1274 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: Chinese | 1328 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: reading text | 1276 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: humor | 1284 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: captioning | 1257 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: recognizing things | 1285 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: creative writing | 1269 | Not measured | Only Kimi K2.5 measured |
| MultiChallenge | 61.4% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 13 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Kimi K2.5 | 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
Kimi K2.5 costs less
Agent loop
200K input + 10K output tokens
Kimi K2.5 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 | MoonshotAI Kimi K2.5 | NVIDIA Nemotron 3 Ultra |
|---|---|---|
| Maker | Moonshot AI | NVIDIA |
| Weights | Open weights | Open weights |
| Released | January 27, 2026 | June 4, 2026 |
| Context window | 262K | 262K |
| Input $/Mtok | $0.532 | $0.60 |
| Output $/Mtok | $2.85 | $2.40 |
| Coding index | 38.6 | 30.0 |
| Independent measurements behind it | 3 | 3 |
| Cost per solved task | $0.24 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Kimi K2.5 better than Nemotron 3 Ultra for coding?
Pick Kimi K2.5 for coding: it scores 38.6 on the Vibe Coding Index against 30.0 for Nemotron 3 Ultra. Pick Nemotron 3 Ultra for output tokens 1.2x cheaper ($2.40 vs $2.85 per million) and work measured by AA Coding Index or LiveCodeBench (Vals AI), where it leads.
Which is cheaper, Kimi K2.5 or Nemotron 3 Ultra?
Kimi K2.5 costs $0.532 per million input tokens and $2.85 per million output tokens; Nemotron 3 Ultra costs $0.60 and $2.40. Cost per solved task is known for Kimi K2.5 only.
Which has the bigger context window, Kimi K2.5 or Nemotron 3 Ultra?
Neither: both take 262K tokens.
How many benchmarks is the Kimi K2.5 vs Nemotron 3 Ultra comparison based on?
59 benchmarks have a result for both models as of October 22, 2026. Kimi K2.5's coding index rests on 3 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.