// head_to_head
Muse Spark Open vs GPT-6 Luna
Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.
GPT-6 Luna wins outright — it scores higher and costs less.
GPT-6 Luna leads by 11.8 points overall while listing 10× cheaper per blended million tokens. There is no trade-off to reason about here; the only reason to pick the other is a constraint this table does not show, like an existing contract, a region, or a provider you are already on.
meta
Muse Spark Open
- Blended / 1M
- $2.00
- Context
- 1.0M
- Released
- Oct 15, 2026
- Overall score
- 57.6
openai
GPT-6 Luna
- Blended / 1M
- $0.200
- Context
- 1.1M
- Released
- Sep 22, 2026
- Overall score
- 69.4
Specs and pricing
| Metric | Muse Spark Open | GPT-6 Luna |
|---|---|---|
| LiveBench overall Mean of the seven LiveBench category scores, 0–100. Higher is better. | 57.6 | 69.4win |
| Cost per point Measured benchmark spend divided by overall score — dollars per point of capability. | — | $0.0894 |
| Blended price / 1M 3:1 input:output mix, the usual shape of production traffic. | $2.00 | $0.200win |
| Input price / 1M | $1.25 | $0.100win |
| Output price / 1M | $4.25 | $0.500win |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $0.150 | $0.010win |
| Context window | 1.0M | 1.1M |
| Max output tokens | 944Kwin | 128K |
Benchmarks by category
An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Muse Spark Open on top, GPT-6 Luna below, both out of 100.
What each one costs to run
Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.
| Workload | Muse Spark Open | GPT-6 Luna |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $560.80/mo | $57.52/mo |
| RAG assistant 8K in / 600 out × 100K requests | $815.00/mo | $74.00/mo |
| Coding agent 40K in / 4K out × 20K requests | $724.00/mo | $69.60/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $1,514/mo | $133.00/mo |
| Bulk classification 500 in / 20 out × 5M requests | $3,000/mo | $255.00/mo |
Which should you pick?
Quality matters more than the bill
GPT-6 Luna
Highest overall LiveBench score of the two at 69.4.
The workload is coding or agentic work
GPT-6 Luna
Leads on coding — 84.5 against 73.6.
Muse Spark Open vs GPT-6 Luna FAQ
Which is better, Muse Spark Open or GPT-6 Luna?
GPT-6 Luna wins outright — it scores higher and costs less. GPT-6 Luna leads by 11.8 points overall while listing 10× cheaper per blended million tokens. There is no trade-off to reason about here; the only reason to pick the other is a constraint this table does not show, like an existing contract, a region, or a provider you are already on.
Is Muse Spark Open cheaper than GPT-6 Luna?
GPT-6 Luna is cheaper. On a 3:1 input:output blend, Muse Spark Open lists at $2.00 per million tokens and GPT-6 Luna at $0.200 — GPT-6 Luna is 10× cheaper. Input and output are priced separately — Muse Spark Open charges $1.25 in and $4.25 out, GPT-6 Luna charges $0.100 and $0.500 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Muse Spark Open vs GPT-6 Luna: which scores higher on benchmarks?
Muse Spark Open scores 57.6 and GPT-6 Luna scores 69.4 overall on LiveBench, the mean of its seven categories. That is a 11.8-point lead for GPT-6 Luna. Category scores differ from the overall figure — a model can lead on reasoning and trail on coding, which the per-category table above breaks out.
Does Muse Spark Open or GPT-6 Luna have a bigger context window?
They are effectively the same — 1.0M for Muse Spark Open and 1.1M for GPT-6 Luna.
Do Muse Spark Open and GPT-6 Luna support prompt caching?
Both publish a cached-input rate: $0.150 per million for Muse Spark Open and $0.010 for GPT-6 Luna, against full input rates of $1.25 and $0.100. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.
Related comparisons
How these numbers are produced
- Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
- Scores — LiveBench release 2026-09-02, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
- Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
- “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.
Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.