Claude Opus 5.5 vs Muse Ember
Claude Opus 5.5 leads Muse Ember on coding, 87.3 to 64.9 on the Vibe Coding Index, and Muse Ember costs 40.0x less per output token ($0.50 vs $20.00 per million). Updated November 14, 2026; 15 benchmarks have a result for both.
vs boards won of 15 shared
Claude Opus 5.5 or Muse Ember: which to pick
Pick Claude Opus 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 64.9 for Muse Ember.
Pick Muse Ember for output tokens 40.0x cheaper ($0.50 vs $20.00 per million) and a larger context window (1.05M against 1M tokens).
Model AClaude Opus 5.5Anthropic87.3/1005 independent benchmarksNo cost per solved taskModel BMuse EmberMeta64.9/1003 independent benchmarksNo cost per solved task
- Shared results
- 15
- Claude Opus 5.5 only
- 123
- Muse Ember only
- 0
- Like-for-like categories
- 5 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 Opus 5.5
Claude Opus 5.5 scores 87.3 against 64.9.
5 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Claude Opus 5.5 has a AA Intelligence Index result, 59.1.
Directional only
Web design
Design Arena: websites
No call
Only Claude Opus 5.5 has a Design Arena: websites result, 1326.
Directional only
General
Vals Index
Claude Opus 5.5
Claude Opus 5.5 leads, 70.1% against 60.5%.
Same board, both measured
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 5.5 $0.014, Muse Ember $0.0003 per turn.
List prices
At a glance
- Coding index
- Claude Opus 5.5 87.3 from 5 benchmarks, Muse Ember 64.9 from 3 benchmarks.
- Widest category
- Reasoning, 35.9 points apart on average over 2 shared benchmarks.
- Widest single gap
- HLE-Diamond (Artificial Analysis run): Claude Opus 5.5 67.9% against Muse Ember 25.1%, 42.8 points apart on a 0 to 100 scale.
- Output price
- Claude Opus 5.5 $20.00 against Muse Ember $0.50 per million output tokens, 40.0x apart.
- Context window
- Claude Opus 5.5 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 5.5 | Bars | Muse Ember | Ties |
|---|---|---|---|---|
| Coding | 7 | 0 | ||
| Agentic work | 3 | 1 | ||
| Reasoning | 2 | 0 | ||
| Knowledge | 1 | 0 | ||
| General | 1 | 0 | ||
| All shared boards | 14 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index70
| Benchmark | Claude Opus 5.5 | Muse Ember | Leader |
|---|---|---|---|
| LiveBench coding | 87.1% | Not measured | Only Claude Opus 5.5 measured |
| LMArena WebDev | 1815 | 1609 | Claude Opus 5.5 |
| Terminal-Bench 4 (Vals AI) | 65.2% | 39.4% | Claude Opus 5.5 |
| Vibe Code Bench (Vals AI) | 90.3% | 83.7% | Claude Opus 5.5 |
| Code migration (Vals AI) | 66.7% | Not measured | Only Claude Opus 5.5 measured |
| ProgramBench (Vals AI) | 18.5% | Not measured | Only Claude Opus 5.5 measured |
| IOI (Vals AI) | 95.1% | Not measured | Only Claude Opus 5.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 87.6% | Not measured | Only Claude Opus 5.5 measured |
| SWE-bench Multimodal (Vals AI) | 70.2% | Not measured | Only Claude Opus 5.5 measured |
| Vibe Code Bench 1-100 (Vals AI) | 30.4% | Not measured | Only Claude Opus 5.5 measured |
| CyberBench (Vals AI) | 74.6% | Not measured | Only Claude Opus 5.5 measured |
| SciCode | 66.9% | Not measured | Only Claude Opus 5.5 measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | 59.6% | 40.9% | Claude Opus 5.5 |
| FrontierCode 2.0 | 46.4% | 27.2% | Claude Opus 5.5 |
| FrontierCode | 54.6% | Not measured | Only Claude Opus 5.5 measured |
| FrontierSWE | 62.3% | Not measured | Only Claude Opus 5.5 measured |
| MirrorCode | 95.6% | Not measured | Only Claude Opus 5.5 measured |
| ALE-Bench | 2147.4 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: coding | 1543 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: software and IT | 1533 | Not measured | Only Claude Opus 5.5 measured |
| LMArena WebDev: React | 1868 | 1616 | Claude Opus 5.5 |
| LMArena WebDev: HTML | 1727 | 1621 | Claude Opus 5.5 |
| LMArena WebDev: from an image | 1752 | Not measured | Only Claude Opus 5.5 measured |
| SciCode | 18.5% | Not measured | Only Claude Opus 5.5 measured |
| GameBench 2 | 94.8 | Not measured | Only Claude Opus 5.5 measured |
| Terminal-Bench 4.0 | 64.8% | Not measured | Only Claude Opus 5.5 measured |
| CursorBench 4.0 | 57.8% | Not measured | Only Claude Opus 5.5 measured |
| ProgramBench | 18.5% | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 24 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Claude Opus 5.5 | Muse Ember | Leader |
|---|---|---|---|
| AA Intelligence Index | 59.1 | Not measured | Only Claude Opus 5.5 measured |
| Epoch Capabilities Index | 168.5 | Not measured | Only Claude Opus 5.5 measured |
Agentic workLike-for-likePublic boards, shown as published, kept out of the index31
| Benchmark | Claude Opus 5.5 | Muse Ember | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1321 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: agents building full-stack apps | 1390 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: agents building mobile apps | 1294 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: agents building Android apps | 1392 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: agents building games | 1456 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: HTML slides | 1471 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: PowerPoint slides | 1391 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: spreadsheets | 1328 | Not measured | Only Claude Opus 5.5 measured |
| LiveBench research | 88.9% | Not measured | Only Claude Opus 5.5 measured |
| LiveBench browser | 88.4% | Not measured | Only Claude Opus 5.5 measured |
| LiveBench long agentic | 72.8% | Not measured | Only Claude Opus 5.5 measured |
| SREBench (Vals AI) | 33.6% | Not measured | Only Claude Opus 5.5 measured |
| Finance Agent (Vals AI) | 58.6% | Not measured | Only Claude Opus 5.5 measured |
| Tax Agent Bench (Vals AI) | 44.5% | 38.2% | Claude Opus 5.5 |
| Legal Research Bench (Vals AI) | 50.5% | 49.0% | Claude Opus 5.5 |
| Harvey's Legal Agent Benchmark (Vals AI) | 9.2% | 25.0% | Muse Ember |
| Excel Modeling Benchmark (Vals AI) | 75.9% | Not measured | Only Claude Opus 5.5 measured |
| BioMysteryBench (Vals AI) | 79.3% | Not measured | Only Claude Opus 5.5 measured |
| Terminal-Bench-Science (Vals AI) | 47.1% | Not measured | Only Claude Opus 5.5 measured |
| Vals Science Index | 58.7% | Not measured | Only Claude Opus 5.5 measured |
| Time Horizon Index (Vals AI) | 91.3% | Not measured | Only Claude Opus 5.5 measured |
| CUA-bench (Vals AI) | 14.0% | Not measured | Only Claude Opus 5.5 measured |
| Robo-bench (Vals AI) | 14.6% | Not measured | Only Claude Opus 5.5 measured |
| APEX-Agents | 73.5% | 64.3% | Claude Opus 5.5 |
| Remote Labor Index | 21.3% | Not measured | Only Claude Opus 5.5 measured |
| PostTrainBench | 43.8% | Not measured | Only Claude Opus 5.5 measured |
| SpireClimb | 5.8% | Not measured | Only Claude Opus 5.5 measured |
| Vending-Bench 2 | $9,235 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Search | 1213 | Not measured | Only Claude Opus 5.5 measured |
| MCP Atlas | 85.4% | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 14 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Claude Opus 5.5 | Muse Ember | Leader |
|---|---|---|---|
| LiveBench reasoning | 92.2% | Not measured | Only Claude Opus 5.5 measured |
| MysteryMechanism (Vals AI) | 49.5% | Not measured | Only Claude Opus 5.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 61.4% | Not measured | Only Claude Opus 5.5 measured |
| HLE-Diamond (Artificial Analysis run) | 67.9% | 25.1% | Claude Opus 5.5 |
| CritPt v2, hard subset (Artificial Analysis run) | 68.0% | 39.0% | Claude Opus 5.5 |
| GPQA Diamond (Epoch AI run) | 90.6% | Not measured | Only Claude Opus 5.5 measured |
| ARC-AGI | 98.5% | Not measured | Only Claude Opus 5.5 measured |
| ARC-AGI-2 | 93.3% | Not measured | Only Claude Opus 5.5 measured |
| SimpleBench | 88.4% | Not measured | Only Claude Opus 5.5 measured |
| Chess puzzles | 67.0% | Not measured | Only Claude Opus 5.5 measured |
| Mystery game puzzles | 71.0% | Not measured | Only Claude Opus 5.5 measured |
| EBR-bench | 71.4% | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: hard prompts | 1531 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: expert | 1555 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: hard prompts in English | 1536 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: diagrams | 1354 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: homework | 1357 | Not measured | Only Claude Opus 5.5 measured |
| Humanity's Last Exam (Scale run) | 55.0% | Not measured | Only Claude Opus 5.5 measured |
| GoBench | 2274 | Not measured | Only Claude Opus 5.5 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 5.5 | Muse Ember | Leader |
|---|---|---|---|
| OTIS Mock AIME | 100.0% | Not measured | Only Claude Opus 5.5 measured |
| FrontierMath, tiers 1 to 3 | 91.2% | Not measured | Only Claude Opus 5.5 measured |
| FrontierMath, tier 4 | 95.0% | Not measured | Only Claude Opus 5.5 measured |
| ProofBench | 100.0% | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: math | 1520 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: mathematical work | 1532 | Not measured | Only Claude Opus 5.5 measured |
| MathArena | 75.3% | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 7 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Opus 5.5 | Muse Ember | Leader |
|---|---|---|---|
| MedCode (Vals AI) | 49.8% | Not measured | Only Claude Opus 5.5 measured |
| AA-Omniscience | 48.1 | 7.7 | Claude Opus 5.5 |
| SimpleQA Verified | 72.2% | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: science | 1525 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: medicine and healthcare | 1511 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: legal and government | 1519 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: business and finance | 1494 | Not measured | Only Claude Opus 5.5 measured |
| FACTS Benchmark Suite | 66.5% | Not measured | Only Claude Opus 5.5 measured |
| PRBench Legal | 47.6% | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 12 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | Claude Opus 5.5 | Muse Ember | Leader |
|---|---|---|---|
| Design Arena: websites | 1326 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: UI components | 1377 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: game dev | 1427 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: data viz | 1387 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: 3D | 1460 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: all code categories | 1384 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: SVG | 1320 | Not measured | Only Claude Opus 5.5 measured |
| Design Arena: ASCII art | 1354 | Not measured | Only Claude Opus 5.5 measured |
| LiveBench design | 83.3% | Not measured | Only Claude Opus 5.5 measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Claude Opus 5.5 | Muse Ember | Leader |
|---|---|---|---|
| Vals Index | 70.1% | 60.5% | Claude Opus 5.5 |
| LiveBench data analysis | 80.3% | Not measured | Only Claude Opus 5.5 measured |
| Public Benefits Bench (Vals AI) | 70.6% | Not measured | Only Claude Opus 5.5 measured |
| SAGE (Vals AI) | 91.3% | Not measured | Only Claude Opus 5.5 measured |
| MedScribe (Vals AI) | 91.4% | Not measured | Only Claude Opus 5.5 measured |
| Long context reasoning (AA-LCR) | 84.7% | Not measured | Only Claude Opus 5.5 measured |
| GDPval-AA | 1866 | Not measured | Only Claude Opus 5.5 measured |
| DTBench | 98.9% | Not measured | Only Claude Opus 5.5 measured |
| LMCA | 68.2% | Not measured | Only Claude Opus 5.5 measured |
| Furniture assembly | 83.3% | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text | 1514 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: instruction following | 1535 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: creative writing | 1532 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision | 1324 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: English | 1521 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: non-English | 1503 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: Chinese | 1573 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: German | 1513 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: Japanese | 1527 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: Korean | 1505 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: French | 1498 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: Spanish | 1510 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: Russian | 1517 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: Polish | 1511 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: multi-turn | 1502 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: longer queries | 1528 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: writing and language | 1528 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Text: entertainment and media | 1508 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: English | 1321 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: Chinese | 1380 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: reading text | 1332 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: humor | 1267 | Not measured | Only Claude Opus 5.5 measured |
| LMArena Vision: creative writing | 1317 | Not measured | Only Claude Opus 5.5 measured |
| EQ-Bench 4 | 1340 | Not measured | Only Claude Opus 5.5 measured |
| Neither model has a result on the other 15 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Claude Opus 5.5 | 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
Claude Opus 5.5$0.014Fits in one request
Muse Ember$0.0003Fits in one request
Muse Ember costs less
Repository review
50K input + 3K output tokens
Claude Opus 5.5$0.260Fits in one request
Muse Ember$0.0065Fits in one request
Muse Ember costs less
Agent loop
200K input + 10K output tokens
Claude Opus 5.5$1.00Fits 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 5.5 | Meta Muse Ember |
|---|---|---|
| Maker | Anthropic | Meta |
| Weights | No public weights listed | No public weights listed |
| Released | September 22, 2026 | November 9, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $4.00 | $0.10 |
| Output $/Mtok | $20.00 | $0.50 |
| Coding index | 87.3 | 64.9 |
| Independent measurements behind it | 5 | 3 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Claude Opus 5.5 better than Muse Ember for coding?
Pick Claude Opus 5.5 for coding: it scores 87.3 on the Vibe Coding Index against 64.9 for Muse Ember. Pick Muse Ember for output tokens 40.0x cheaper ($0.50 vs $20.00 per million) and a larger context window (1.05M against 1M tokens).
Which is cheaper, Claude Opus 5.5 or Muse Ember?
Claude Opus 5.5 costs $4.00 per million input tokens and $20.00 per million output tokens; Muse Ember costs $0.10 and $0.50. Cost per solved task is known for neither of them.
Which has the bigger context window, Claude Opus 5.5 or Muse Ember?
Muse Ember, with 1.05M tokens against 1M.
How many benchmarks is the Claude Opus 5.5 vs Muse Ember comparison based on?
15 benchmarks have a result for both models as of November 14, 2026. Claude Opus 5.5'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.