Claude Opus 4.8 vs Muse Ember
Muse Ember leads Claude Opus 4.8 on coding, 64.9 to 62.8 on the Vibe Coding Index, and Muse Ember costs 50.0x less per output token ($0.50 vs $25.00 per million). Updated November 14, 2026; 9 benchmarks have a result for both.
vs boards won of 9 shared
Claude Opus 4.8 or Muse Ember: which to pick
Pick Muse Ember for coding: it scores 64.9 on the Vibe Coding Index against 62.8 for Claude Opus 4.8, though on 3 benchmarks against 5.
Claude Opus 4.8 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Model AClaude Opus 4.8Anthropic62.8/1005 independent benchmarks$2.17 per solved taskModel BMuse EmberMeta64.9/1003 independent benchmarksNo cost per solved task
- Shared results
- 9
- Claude Opus 4.8 only
- 128
- Muse Ember only
- 6
- 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 62.8.
5 and 3 benchmarks behind the scores
Agentic work
AA Agentic Index
No call
Only Claude Opus 4.8 has a AA Agentic Index result, 41.9.
Directional only
Reasoning
GPQA Diamond
No call
Only Claude Opus 4.8 has a GPQA Diamond result, 92.4%.
Directional only
Knowledge
MMLU Pro
No call
Only Claude Opus 4.8 has a MMLU Pro result, 89.6%.
Directional only
Web design
Design Arena: websites
No call
Only Claude Opus 4.8 has a Design Arena: websites result, 1250.
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 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Muse Ember
Claude Opus 4.8 $0.018, Muse Ember $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Claude Opus 4.8 has the number, $2.17.
Directional only
At a glance
- Coding index
- Claude Opus 4.8 62.8 from 5 benchmarks, Muse Ember 64.9 from 3 benchmarks.
- Widest category
- Coding, 11.1 points apart on average over 6 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Claude Opus 4.8 23.2% against Muse Ember 39.4%, 21.5 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 4.8 $25.00 against Muse Ember $0.50 per million output tokens, 50.0x apart.
- Context window
- Claude Opus 4.8 takes 1M 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 | Claude Opus 4.8 | Bars | Muse Ember | Ties |
|---|---|---|---|---|
| Coding | 0 | 6 | ||
| Agentic work | 0 | 3 | ||
| All shared boards | 0 | 9 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index06
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| LMArena WebDev | 1555 | 1609 | Muse Ember |
| AA Coding Index | 74.3 | Not measured | Only Claude Opus 4.8 measured |
| LiveCodeBench (Vals AI) | 87.8% | Not measured | Only Claude Opus 4.8 measured |
| SWE-bench Verified (Vals AI) | 88.6% | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench 4 (Vals AI) | 23.2% | 39.4% | Muse Ember |
| Vibe Code Bench (Vals AI) | 82.7% | 83.7% | Muse Ember |
| Code migration (Vals AI) | 47.3% | Not measured | Only Claude Opus 4.8 measured |
| ProgramBench (Vals AI) | 1.0% | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench 2.1 (Vals AI) | 71.9% | Not measured | Only Claude Opus 4.8 measured |
| SkillsBench (Vals AI) | 59.2% | Not measured | Only Claude Opus 4.8 measured |
| SciCode | 54.4% | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 58.3% | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | 21.7% | 40.9% | Muse Ember |
| FrontierCode 2.0 | Not measured | 27.2% | Only Muse Ember measured |
| FrontierCode | 46.5% | Not measured | Only Claude Opus 4.8 measured |
| GSO-Bench | 47.1% | Not measured | Only Claude Opus 4.8 measured |
| WeirdML | 82.9% | Not measured | Only Claude Opus 4.8 measured |
| MirrorCode | 65.6% | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: coding | 1491 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: software and IT | 1488 | Not measured | Only Claude Opus 4.8 measured |
| LMArena WebDev: React | 1556 | 1616 | Muse Ember |
| LMArena WebDev: HTML | 1542 | 1621 | Muse Ember |
| SciCode | 12.3% | Not measured | Only Claude Opus 4.8 measured |
| SWE Atlas: Codebase QnA | 57.3% | Not measured | Only Claude Opus 4.8 measured |
| SWE Atlas: Refactoring | 46.7% | Not measured | Only Claude Opus 4.8 measured |
| SWE Atlas: Test Writing | 49.6% | Not measured | Only Claude Opus 4.8 measured |
| GameBench 2 | 62.5 | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench 2.1 | 78.9% | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench 3.0 | 21.1% | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench 4.0 | 23.6% | Not measured | Only Claude Opus 4.8 measured |
| ProgramBench | 0.0% | Not measured | Only Claude Opus 4.8 measured |
| Neither model has a result on the other 21 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 159.9 | Not measured | Only Claude Opus 4.8 measured |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| AA Agentic Index | 41.9 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: agents building web apps | 1210 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: agents building full-stack apps | 1224 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: agents building mobile apps | 1209 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: agents building Android apps | 1222 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: agents building Godot games | 1211 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: agents building games | 1179 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: HTML slides | 1116 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: PowerPoint slides | 1192 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: spreadsheets | 1018 | Not measured | Only Claude Opus 4.8 measured |
| Finance Agent (Vals AI) | 53.9% | Not measured | Only Claude Opus 4.8 measured |
| Tax Agent Bench (Vals AI) | 30.0% | 38.2% | Muse Ember |
| Legal Research Bench (Vals AI) | 43.8% | 49.0% | Muse Ember |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 25.0% | Only Muse Ember measured |
| Excel Modeling Benchmark (Vals AI) | 69.4% | Not measured | Only Claude Opus 4.8 measured |
| Terminal-Bench-Science (Vals AI) | 4.3% | Not measured | Only Claude Opus 4.8 measured |
| Time Horizon Index (Vals AI) | 11.8% | Not measured | Only Claude Opus 4.8 measured |
| τ²-Bench Telecom | 94.4% | Not measured | Only Claude Opus 4.8 measured |
| APEX-Agents | 48.9% | 64.3% | Muse Ember |
| Remote Labor Index | 8.3% | Not measured | Only Claude Opus 4.8 measured |
| OSWorld 2.0 | 20.6% | Not measured | Only Claude Opus 4.8 measured |
| DeepResearch Bench | 50.2% | Not measured | Only Claude Opus 4.8 measured |
| PostTrainBench | 31.0% | Not measured | Only Claude Opus 4.8 measured |
| Vending-Bench 2 | $5,787 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Search | 1202 | Not measured | Only Claude Opus 4.8 measured |
| MCP Atlas | 82.2% | Not measured | Only Claude Opus 4.8 measured |
| Toolathlon-Verified | 76.2% | Not measured | Only Claude Opus 4.8 measured |
| τ³-Banking | 39.7% | Not measured | Only Claude Opus 4.8 measured |
| Neither model has a result on the other 16 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index19 boards, none shared
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| GPQA Diamond | 92.4% | Not measured | Only Claude Opus 4.8 measured |
| MMMU Pro (Vals AI) | 86.6% | Not measured | Only Claude Opus 4.8 measured |
| GPQA Diamond (Artificial Analysis run) | 92.0% | Not measured | Only Claude Opus 4.8 measured |
| Humanity's Last Exam (Artificial Analysis run) | 48.7% | Not measured | Only Claude Opus 4.8 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 |
| GPQA Diamond (Epoch AI run) | 91.0% | Not measured | Only Claude Opus 4.8 measured |
| ARC-AGI | 92.5% | Not measured | Only Claude Opus 4.8 measured |
| ARC-AGI-2 | 72.1% | Not measured | Only Claude Opus 4.8 measured |
| SimpleBench | 64.8% | Not measured | Only Claude Opus 4.8 measured |
| Chess puzzles | 52.0% | Not measured | Only Claude Opus 4.8 measured |
| Mystery game puzzles | 36.0% | Not measured | Only Claude Opus 4.8 measured |
| EBR-bench | 28.6% | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: hard prompts | 1482 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: expert | 1502 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: hard prompts in English | 1487 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision: diagrams | 1313 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision: homework | 1336 | Not measured | Only Claude Opus 4.8 measured |
| Kagi LLM Benchmark | 88.8% | Not measured | Only Claude Opus 4.8 measured |
| Neither model has a result on the other 7 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| OTIS Mock AIME | 98.3% | Not measured | Only Claude Opus 4.8 measured |
| FrontierMath, tiers 1 to 3 | 80.0% | Not measured | Only Claude Opus 4.8 measured |
| FrontierMath, tier 4 | 56.1% | Not measured | Only Claude Opus 4.8 measured |
| ProofBench | 69.0% | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: math | 1485 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: mathematical work | 1494 | Not measured | Only Claude Opus 4.8 measured |
| MathArena | 35.3% | Not measured | Only Claude Opus 4.8 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index13 boards, none shared
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| MMLU Pro | 89.6% | Not measured | Only Claude Opus 4.8 measured |
| LegalBench (Vals AI) | 83.6% | Not measured | Only Claude Opus 4.8 measured |
| CorpFin (Vals AI) | 66.7% | Not measured | Only Claude Opus 4.8 measured |
| TaxEval (Vals AI) | 75.6% | Not measured | Only Claude Opus 4.8 measured |
| MortgageTax (Vals AI) | 69.9% | Not measured | Only Claude Opus 4.8 measured |
| MedCode (Vals AI) | 53.2% | Not measured | Only Claude Opus 4.8 measured |
| AA-Omniscience | Not measured | 7.7 | Only Muse Ember measured |
| SimpleQA Verified | 53.0% | Not measured | Only Claude Opus 4.8 measured |
| GeoBench | 81.0% | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: science | 1477 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: medicine and healthcare | 1465 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: legal and government | 1477 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: business and finance | 1458 | Not measured | Only Claude Opus 4.8 measured |
| Neither model has a result on the other 8 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| Design Arena: websites | 1250 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: UI components | 1248 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: game dev | 1251 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: data viz | 1234 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: 3D | 1201 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: all code categories | 1243 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: SVG | 1182 | Not measured | Only Claude Opus 4.8 measured |
| Design Arena: ASCII art | 1270 | Not measured | Only Claude Opus 4.8 measured |
| Neither model has a result on the other 1 board here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index36 boards, none shared
| Benchmark | Claude Opus 4.8 | Muse Ember | Leader |
|---|---|---|---|
| Vals Index | Not measured | 60.5% | Only Muse Ember measured |
| Public Benefits Bench (Vals AI) | 68.1% | Not measured | Only Claude Opus 4.8 measured |
| MedScribe (Vals AI) | 85.8% | Not measured | Only Claude Opus 4.8 measured |
| Vals Multimodal Index | 70.9% | Not measured | Only Claude Opus 4.8 measured |
| IFBench | 62.2% | Not measured | Only Claude Opus 4.8 measured |
| Long context reasoning (AA-LCR) | 77.7% | Not measured | Only Claude Opus 4.8 measured |
| GDPval-AA | 1461 | Not measured | Only Claude Opus 4.8 measured |
| DTBench | 94.9% | Not measured | Only Claude Opus 4.8 measured |
| LMCA | 57.5% | Not measured | Only Claude Opus 4.8 measured |
| Surface Evolver Bench | 87.5% | Not measured | Only Claude Opus 4.8 measured |
| Furniture assembly | 42.5% | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text | 1462 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: instruction following | 1477 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: creative writing | 1455 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision | 1295 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: English | 1469 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: non-English | 1451 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: Chinese | 1508 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: German | 1469 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: Japanese | 1443 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: Korean | 1422 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: French | 1481 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: Spanish | 1467 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: Russian | 1475 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: Polish | 1460 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: multi-turn | 1476 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: longer queries | 1484 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: writing and language | 1462 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Text: entertainment and media | 1441 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision: English | 1294 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision: Chinese | 1344 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision: reading text | 1303 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision: humor | 1283 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Vision: creative writing | 1301 | Not measured | Only Claude Opus 4.8 measured |
| LMArena Document | 1475 | Not measured | Only Claude Opus 4.8 measured |
| EQ-Bench 4 | 1268 | Not measured | Only Claude Opus 4.8 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 | Claude Opus 4.8 | 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
Claude Opus 4.8$0.018Fits in one request
Muse Ember$0.0003Fits in one request
Muse Ember costs less
Repository review
50K input + 3K output tokens
Claude Opus 4.8$0.325Fits in one request
Muse Ember$0.0065Fits in one request
Muse Ember costs less
Agent loop
200K input + 10K output tokens
Claude Opus 4.8$1.25Fits 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 | Anthropic Claude Opus 4.8 | Meta Muse Ember |
|---|---|---|
| Maker | Anthropic | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | May 27, 2026 | November 9, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $5.00 | $0.10 |
| Output $/Mtok | $25.00 | $0.50 |
| Coding index | 62.8 | 64.9 |
| Independent measurements behind it | 5 | 3 |
| Cost per solved task | $2.17 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 4.8 better than Muse Ember for coding?
Pick Muse Ember for coding: it scores 64.9 on the Vibe Coding Index against 62.8 for Claude Opus 4.8, though on 3 benchmarks against 5. Claude Opus 4.8 is neither cheaper nor larger in context, and leads no benchmark both models were measured on.
Which is cheaper, Claude Opus 4.8 or Muse Ember?
Claude Opus 4.8 costs $5.00 per million input tokens and $25.00 per million output tokens; Muse Ember costs $0.10 and $0.50. Cost per solved task is known for Claude Opus 4.8 only.
Which has the bigger context window, Claude Opus 4.8 or Muse Ember?
Muse Ember, with 1.05M tokens against 1M.
How many benchmarks is the Claude Opus 4.8 vs Muse Ember comparison based on?
9 benchmarks have a result for both models as of November 14, 2026. Claude Opus 4.8's coding index rests on 5 independent benchmarks and Muse Ember's on 3. Where only one model has a result, the page says so instead of naming a winner.