Kimi K2.5 vs Muse Ember
Muse Ember leads Kimi K2.5 on coding, 64.9 to 38.6 on the Vibe Coding Index, and Muse Ember costs 5.7x less per output token ($0.50 vs $2.85 per million). Updated November 14, 2026; 5 benchmarks have a result for both.
vs boards won of 5 shared
Kimi K2.5 or Muse Ember: which to pick
Pick Muse Ember for coding: it scores 64.9 on the Vibe Coding Index against 38.6 for Kimi K2.5.
Kimi K2.5 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Model AKimi K2.5Moonshot AI38.6/1003 independent benchmarks$0.24 per solved taskModel BMuse EmberMeta64.9/1003 independent benchmarksNo cost per solved task
- Shared results
- 5
- Kimi K2.5 only
- 104
- Muse Ember only
- 10
- Like-for-like categories
- 2 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
Muse Ember
Muse Ember scores 64.9 against 38.6.
3 benchmarks behind each score
Reasoning
GPQA Diamond
No call
Only Kimi K2.5 has a GPQA Diamond result, 84.1%.
Directional only
Math
AIME
No call
Only Kimi K2.5 has a AIME result, 95.6%.
Directional only
Knowledge
MMLU Pro
No call
Only Kimi K2.5 has a MMLU Pro result, 85.9%.
Directional only
Web design
Design Arena: websites
No call
Only Kimi K2.5 has a Design Arena: websites result, 1241.
Directional only
General
Vals Index
No call
Only Muse Ember has a Vals Index result, 60.5%.
Directional only
Long documents
Listed context window
Muse Ember
Muse Ember takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Ember
Kimi K2.5 $0.0020, Muse Ember $0.0003 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, Muse Ember 64.9 from 3 benchmarks.
- Widest category
- Coding, 37.1 points apart on average over 4 shared benchmarks.
- Widest single gap
- Vibe Code Bench (Vals AI): Kimi K2.5 17.5% against Muse Ember 83.7%, 66.2 points apart on a 0 to 100 scale.
- Output price
- Kimi K2.5 $2.85 against Muse Ember $0.50 per million output tokens, 5.7x apart.
- Context window
- Kimi K2.5 takes 262K tokens, Muse Ember 1.05M.
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 | Muse Ember | Ties |
|---|---|---|---|---|
| Coding | 0 | 4 | ||
| Agentic work | 0 | 1 | ||
| All shared boards | 0 | 5 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index04
| Benchmark | Kimi K2.5 | Muse Ember | 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 | 1436 | 1609 | Muse Ember |
| AA Coding Index | 46.8 | Not measured | Only Kimi K2.5 measured |
| LiveCodeBench (Vals AI) | 83.9% | Not measured | Only Kimi K2.5 measured |
| SWE-bench Verified (Vals AI) | 70.0% | Not measured | Only Kimi K2.5 measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 39.4% | Only Muse Ember measured |
| Vibe Code Bench (Vals AI) | 17.5% | 83.7% | Muse Ember |
| Code migration (Vals AI) | 7.0% | Not measured | Only Kimi K2.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 42.0% | Not measured | Only Kimi K2.5 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 34.8% | Not measured | Only Kimi K2.5 measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | Not measured | 40.9% | Only Muse Ember measured |
| FrontierCode 2.0 | Not measured | 27.2% | Only Muse Ember measured |
| Terminal-Bench | 43.2% | Not measured | Only Kimi K2.5 measured |
| WeirdML | 45.6% | Not measured | Only Kimi K2.5 measured |
| ALE-Bench | 821.6 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: coding | 1484 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: software and IT | 1471 | Not measured | Only Kimi K2.5 measured |
| LMArena WebDev: React | 1428 | 1616 | Muse Ember |
| LMArena WebDev: HTML | 1427 | 1621 | Muse Ember |
| 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 |
| Terminal-Bench 2.0 | 43.2% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 27 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Kimi K2.5 | Muse Ember | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 148.8 | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Kimi K2.5 | Muse Ember | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1112 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building full-stack apps | 1088 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building mobile apps | 1139 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building Android apps | 1105 | 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% | Not measured | Only Kimi K2.5 measured |
| Tax Agent Bench (Vals AI) | Not measured | 38.2% | Only Muse Ember measured |
| Legal Research Bench (Vals AI) | 15.9% | 49.0% | Muse Ember |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 25.0% | Only Muse Ember measured |
| Excel Modeling Benchmark (Vals AI) | 28.5% | Not measured | Only Kimi K2.5 measured |
| τ²-Bench Telecom | 95.9% | Not measured | Only Kimi K2.5 measured |
| APEX-Agents | Not measured | 64.3% | Only Muse Ember 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% | Not measured | Only Kimi K2.5 measured |
| Toolathlon-Verified | 33.0% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 28 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index15 boards, none shared
| Benchmark | Kimi K2.5 | Muse Ember | Leader |
|---|---|---|---|
| GPQA Diamond | 84.1% | Not measured | Only Kimi K2.5 measured |
| MMMU Pro (Vals AI) | 84.3% | Not measured | Only Kimi K2.5 measured |
| GPQA Diamond (Artificial Analysis run) | 87.9% | Not measured | Only Kimi K2.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 30.7% | Not measured | Only Kimi K2.5 measured |
| HLE-Diamond (Artificial Analysis run) | Not measured | 25.1% | Only Muse Ember measured |
| CritPt v2, hard subset (Artificial Analysis run) | Not measured | 39.0% | Only Muse Ember 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 |
| LMArena Text: hard prompts | 1453 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: expert | 1465 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: hard prompts in English | 1460 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: diagrams | 1282 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: homework | 1296 | 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 11 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index4 boards, none shared
| Benchmark | Kimi K2.5 | Muse Ember | Leader |
|---|---|---|---|
| AIME | 95.6% | Not measured | Only Kimi K2.5 measured |
| LMArena Text: math | 1469 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: mathematical work | 1473 | Not measured | Only Kimi K2.5 measured |
| MathArena | 17.5% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 10 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index15 boards, none shared
| Benchmark | Kimi K2.5 | Muse Ember | Leader |
|---|---|---|---|
| MMLU Pro | 85.9% | Not measured | Only Kimi K2.5 measured |
| CaseLaw (Vals AI) | 58.7% | Not measured | Only Kimi K2.5 measured |
| CorpFin (Vals AI) | 68.3% | Not measured | Only Kimi K2.5 measured |
| TaxEval (Vals AI) | 74.2% | Not measured | Only Kimi K2.5 measured |
| 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% | Not measured | Only Kimi K2.5 measured |
| AA-Omniscience | Not measured | 7.7 | Only Muse Ember measured |
| SimpleQA Verified | 34.3% | Not measured | Only Kimi K2.5 measured |
| LMArena Text: science | 1458 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: medicine and healthcare | 1449 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: legal and government | 1441 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: business and finance | 1427 | Not measured | Only Kimi K2.5 measured |
| 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 6 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Kimi K2.5 | Muse Ember | Leader |
|---|---|---|---|
| Design Arena: websites | 1241 | Not measured | Only Kimi K2.5 measured |
| Design Arena: UI components | 1227 | Not measured | Only Kimi K2.5 measured |
| Design Arena: game dev | 1196 | Not measured | Only Kimi K2.5 measured |
| Design Arena: data viz | 1216 | Not measured | Only Kimi K2.5 measured |
| Design Arena: 3D | 1185 | Not measured | Only Kimi K2.5 measured |
| Design Arena: all code categories | 1226 | Not measured | Only Kimi K2.5 measured |
| Design Arena: SVG | 1139 | Not measured | Only Kimi K2.5 measured |
| Design Arena: ASCII art | 1160 | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index35 boards, none shared
| Benchmark | Kimi K2.5 | Muse Ember | Leader |
|---|---|---|---|
| Vals Index | Not measured | 60.5% | Only Muse Ember measured |
| MedScribe (Vals AI) | 76.4% | Not measured | Only Kimi K2.5 measured |
| IFBench | 70.2% | Not measured | Only Kimi K2.5 measured |
| Long context reasoning (AA-LCR) | 78.0% | Not measured | Only Kimi K2.5 measured |
| GDPval-AA | 847 | Not measured | Only Kimi K2.5 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 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: instruction following | 1431 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: creative writing | 1422 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision | 1269 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: English | 1453 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: non-English | 1432 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: Chinese | 1493 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: German | 1441 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: Japanese | 1422 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: Korean | 1410 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: French | 1454 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: Spanish | 1449 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: Russian | 1435 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: Polish | 1445 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: multi-turn | 1444 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: longer queries | 1444 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: writing and language | 1425 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: entertainment and media | 1417 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: English | 1274 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: Chinese | 1327 | 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 | 1250 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: recognizing things | 1287 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: creative writing | 1270 | Not measured | Only Kimi K2.5 measured |
| LMArena Document | 1431 | 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 14 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Kimi K2.5 | Muse Ember | 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
Kimi K2.5$0.0020Fits in one request
Muse Ember$0.0003Fits in one request
Muse Ember costs less
Repository review
50K input + 3K output tokens
Kimi K2.5$0.035Fits in one request
Muse Ember$0.0065Fits in one request
Muse Ember costs less
Agent loop
200K input + 10K output tokens
Kimi K2.5$0.135Fits in one request
Muse Ember$0.025Fits in one request
Muse Ember 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 | Meta Muse Ember |
|---|---|---|
| Maker | Moonshot AI | Meta |
| Weights | Open weights | No public weights listed |
| Released | January 27, 2026 | November 9, 2026 |
| Context window | 262K | 1.05M |
| Input $/Mtok | $0.532 | $0.10 |
| Output $/Mtok | $2.85 | $0.50 |
| Coding index | 38.6 | 64.9 |
| 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 Muse Ember for coding?
Pick Muse Ember for coding: it scores 64.9 on the Vibe Coding Index against 38.6 for Kimi K2.5. Kimi K2.5 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Which is cheaper, Kimi K2.5 or Muse Ember?
Kimi K2.5 costs $0.532 per million input tokens and $2.85 per million output tokens; Muse Ember costs $0.10 and $0.50. Cost per solved task is known for Kimi K2.5 only.
Which has the bigger context window, Kimi K2.5 or Muse Ember?
Muse Ember, with 1.05M tokens against 262K.
How many benchmarks is the Kimi K2.5 vs Muse Ember comparison based on?
5 benchmarks have a result for both models as of November 14, 2026. Kimi K2.5's coding index rests on 3 independent benchmarks and Muse Ember's on 3. Where only one model has a result, the page says so instead of naming a winner.