Model vs model
GPT-6 Luna vs Muse Ember
At a glance
Open or closed · can you download the model and run it yourself?
Where they sit among all 45 models
GPT-6 Luna ranks 17th of the 40 models with an Intelligence Index. Up and to the left is smarter for less money. Hover or tap a dot for its numbers, then click it to compare that model with GPT-6 Luna.
How smart is each one?
Every intelligence score we have
Out of 100, higher is better. GPT-6 Luna Muse Ember
Muse Ember has no Artificial Analysis scores yet, so only our own tests compare them.
Overall
Intelligence Index
38.1
By field of work
Finance & accounting
40.3Legal
40.3Healthcare & medicine
38.9Economics
45.2Engineering
37.1Strategy & operations
45.7
Benchmarks
Factual knowledge · SimpleQA
41.4Hard reasoning · Humanity's Last Exam
38.5Competition math · OTIS Mock AIME
98.9Research math · FrontierMath
78.9Scientific coding · SciCode
54.6Mergeable code · FrontierCode 2.0
21.9Terminal tasks · Terminal-Bench 4.0
12.6Long documents · AA-LCR
83.3
Our tests
Hallucination test · our test, higher means it made up less
81.7Muse Ember: not scored yet
Next.js coding tasks · Vercel's Next.js evals, % of tasks passed
77Muse Ember: not scored yet
The specs
| Spec | GPT-6 Luna | Muse Ember |
|---|---|---|
| Input price | $0.10 per 1M | $0.10 per 1M |
| Output price | $0.50 per 1M | $0.50 per 1M |
| Cost per test task | $0.4501 | $0.1531 |
| Context window | 1.05M | 1.05M |
| Max output | 128K | — |
| Accepts | Text, Image, PDF | Text, Image, PDF |
| Open weights | No | No |
| Lab | OpenAI | Meta |
| Released | Sep 2026 | Nov 2026 |
| Knowledge cutoff | May 2026 | Not published |
Blended price weighs 3 parts input to 1 part output. List prices from models.dev. Cost per test task from Vals AI.
Questions
Is GPT-6 Luna or Muse Ember cheaper?
They cost the same, $0.20 per 1M tokens blended.
Are GPT-6 Luna and Muse Ember open source?
No. Both are closed models: the weights aren't published, so you can only use them through an API, from OpenAI and Meta or a cloud that resells them.
Which has the longer context window?
Both accept about 1.05M tokens.
Can I compare GPT-6 Luna and Muse Ember on my own prompt?
Yes. ModelCompare sends one prompt to both models at once and shows each answer side by side with what it cost. You can try it free without an account.
Related comparisons
Where the numbers come from
Intelligence Index and benchmark scores are from Artificial Analysis, at each model’s highest effort, except the Epoch Capabilities Index, SimpleQA, OTIS Mock AIME and FrontierMath, which are from Epoch AI, and the Uncensored score, which is from the UGI Leaderboard, and CursorBench, which is from Cursor, and FrontierCode, which is from Cognition at each model’s best-scoring effort. The hallucination test is ours: questions with one exact answer, fake evidence pushed against right answers and requests that tempt a model to name packages that don’t exist. Prices are list prices from models.dev. Example answers come from our own test runs. Updated November 13, 2026.