AI model comparison
Muse Spark Open vs GPT-6 Luna
Side by side comparison of Muse Spark Open and GPT-6 Luna on pricing, benchmark scores, context window, and more.
Muse Spark Open is a coding-optimized open-weight model.
- Input / 1M
- $1.25
- Output / 1M
- $4.25
- Context
- 1.05M
GPT-6 Luna is the fast, cost-efficient model in OpenAI's GPT-6 series, positioned below GPT-6 Sol.
- Input / 1M
- $0.10
- Output / 1M
- $0.50
- Context
- 1.05M
Comparing image generators? Compare image models
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
GPT-6 Luna
10.3x cheaper for a typical chat
Higher intelligence score
GPT-6 Luna
27.8 vs 24.7 on Artificial Analysis
Larger context window
GPT-6 Luna
1.05M vs 1.05M tokens
Newer release
Muse Spark Open
Released October 15, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
GPT-6 Luna27.8Coding index
GPT-6 LunaNot availableAgentic index
GPT-6 LunaNot availablePricing
Muse Spark Open vs GPT-6 Luna API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | GPT-6 Luna | |
|---|---|---|
| Input tokensPer 1M tokens | $1.25 | $0.10 |
| Output tokensPer 1M tokens | $4.25 | $0.50 |
| Cached input (read)Per 1M tokens | $0.15 | $0.01 |
| Cache writePer 1M tokens | Not available | $0.13 |
| Long-context pricingPer 1M tokens, for very long prompts | Same rate at any length | $0.20 in / $0.75 out above 272K |
| Web searchPer request | Not available | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
GPT-6 Luna$0.45Coding task
30K in, 4K out
GPT-6 Luna$5$2.30 cachedLong document summary
150K in, 2K out
GPT-6 Luna$16$2.50 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | GPT-6 Luna | |
|---|---|---|
| Context window | 1.05M tokens | 1.05M tokens |
| Max output | 944K tokens | 128K tokens |
| Input types | Audio, File, Image, Text, Video | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Extra high, High, Medium, Low | Max, Extra high, High, Medium, Low, None |
| Default reasoning effort | Medium | Medium |
| Release date | October 15, 2026 | September 22, 2026 |
Features
Supported features
API features available for each model.
| Metric | GPT-6 Luna | |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Supported | Not supported |
| Stop sequences | Supported | Not supported |
| Deterministic seed | Supported | Supported |
| Verbosity control | Not supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
GPT-6 LunaView full model details- GPT-6 Luna vs DeepSeek V4.1 Flash 1017
- GPT-6 Luna vs GLM 5.3 Flash
- GPT-6 Luna vs DeepSeek V4.1 Flash
- GPT-6 Luna vs Hy4 preview
- GPT-6 Luna vs Claude Opus 5.5
- GPT-6 Luna vs Step 5 Preview
- GPT-6 Luna vs MiniMax M3.1 Flash
- GPT-6 Luna vs GPT-5.6 Luna
- GPT-6 Luna vs GPT-6.1 Sol
- GPT-6 Luna vs DeepSeek V4 Flash 0731
- GPT-6 Luna vs GLM 5.3
- GPT-6 Luna vs Hy3
- GPT-6 Luna vs MiMo-V2.6-Flash
- GPT-6 Luna vs Claude Haiku 5.5
- GPT-6 Luna vs GPT-6 Astra
- GPT-6 Luna vs Muse Spark 1.3 Contributor
- GPT-6 Luna vs DeepSeek V4 Flash 0423
- GPT-6 Luna vs Claude Sonnet 5.5
- GPT-6 Luna vs GPT-6.1 Terra
- GPT-6 Luna vs Gemini 4 Argon
- GPT-6 Luna vs Gemini 3.8 Flash
- GPT-6 Luna vs Solar Mini 4
- GPT-6 Luna vs MiMo-V2.6-Pro
- GPT-6 Luna vs DeepSeek V4 Pro 0813
- GPT-6 Luna vs Qwen3.8 Max (0902)
- GPT-6 Luna vs Qwen3.8 27B
- GPT-6 Luna vs Qwen3.8 Flash
- GPT-6 Luna vs GPT-6 Luna Pro
- GPT-6 Luna vs Solar Pro 4
- GPT-6 Luna vs Step 3.7 Flash
- GPT-6 Luna vs MiniMax M3
- GPT-6 Luna vs Mistral Large 4
- GPT-6 Luna vs Gemma 4 31B
- GPT-6 Luna vs gpt-oss-120b
- GPT-6 Luna vs Beam 1.0 501B A23B
- GPT-6 Luna vs Gemma 4 26B A4B
- GPT-6 Luna vs Nemotron 3.5 Super VL
- GPT-6 Luna vs Gemini 2.5 Flash Lite
- GPT-6 Luna vs DeepSeek V3.2
- GPT-6 Luna vs GPT-4o-mini
- GPT-6 Luna vs gpt-oss-20b
- GPT-6 Luna vs Qwen3.6 35B A3B
- GPT-6 Luna vs GLM 5.3 FlashX
- GPT-6 Luna vs GPT-5.6 Luna Pro
- GPT-6 Luna vs Ling 3.1 Flash
Our take
GPT-6 Luna is 10.3x cheaper for a typical chat. GPT-6 Luna scores higher on the Artificial Analysis Intelligence Index (27.8 vs 24.7). GPT-6 Luna has the larger context window (1.05M vs 1.05M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is Muse Spark Open or GPT-6 Luna cheaper?
GPT-6 Luna is cheaper for a typical chat (2K input tokens and 500 output tokens). GPT-6 Luna costs $0.10 per 1M input tokens and $0.50 per 1M output tokens, while Muse Spark Open costs $1.25 per 1M input tokens and $4.25 per 1M output tokens.
Which has a bigger context window, Muse Spark Open or GPT-6 Luna?
GPT-6 Luna supports up to 1.05M tokens of context, compared with 1.05M for Muse Spark Open.
Is Muse Spark Open smarter than GPT-6 Luna?
On the Artificial Analysis Intelligence Index, Muse Spark Open scores 24.7 and GPT-6 Luna scores 27.8, putting GPT-6 Luna ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use Muse Spark Open and GPT-6 Luna at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Muse Spark Open and GPT-6 Luna answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Muse Spark Open and GPT-6 Luna at the same time. Compare the answers side by side and keep the best one.