// head_to_head
Muse Spark Open vs SpaceXAI: Grok 4.5
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.
SpaceXAI: Grok 4.5 scores higher, Muse Spark Open costs less — it depends on your workload.
SpaceXAI: Grok 4.5 is ahead by 12.5 points overall, and Muse Spark Open lists 1.5× cheaper per blended million tokens. Whether 12.5 points is worth that depends on how much a wrong answer costs you.
meta
Muse Spark Open
- Blended / 1M
- $2.00
- Context
- 1.0M
- Released
- Oct 15, 2026
- Overall score
- 57.6
x-ai
SpaceXAI: Grok 4.5
- Blended / 1M
- $3.00
- Context
- 500K
- Released
- Jul 8, 2026
- Overall score
- 70.1
Specs and pricing
| Metric | Muse Spark Open | SpaceXAI: Grok 4.5 |
|---|---|---|
| LiveBench overall Mean of the seven LiveBench category scores, 0–100. Higher is better. | 57.6 | 70.1win |
| Cost per point Measured benchmark spend divided by overall score — dollars per point of capability. | — | $0.5008 |
| Blended price / 1M 3:1 input:output mix, the usual shape of production traffic. | $2.00win | $3.00 |
| Input price / 1M | $1.25win | $2.00 |
| Output price / 1M | $4.25win | $6.00 |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $0.150win | $0.300 |
| Context window | 1.0Mwin | 500K |
| Max output tokens | 944Kwin | 450K |
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, SpaceXAI: Grok 4.5 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 | SpaceXAI: Grok 4.5 |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $560.80/mo | $837.60/mo |
| RAG assistant 8K in / 600 out × 100K requests | $815.00/mo | $1,280/mo |
| Coding agent 40K in / 4K out × 20K requests | $724.00/mo | $1,128/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $1,514/mo | $2,365/mo |
| Bulk classification 500 in / 20 out × 5M requests | $3,000/mo | $4,750/mo |
Which should you pick?
Quality matters more than the bill
SpaceXAI: Grok 4.5
Highest overall LiveBench score of the two at 70.1.
The workload is coding or agentic work
SpaceXAI: Grok 4.5
Leads on coding — 94.3 against 73.6.
You need to fit large documents in one call
Muse Spark Open
Wider context window — 1.0M against 500K.
Muse Spark Open vs SpaceXAI: Grok 4.5 FAQ
Which is better, Muse Spark Open or SpaceXAI: Grok 4.5?
SpaceXAI: Grok 4.5 scores higher, Muse Spark Open costs less — it depends on your workload. SpaceXAI: Grok 4.5 is ahead by 12.5 points overall, and Muse Spark Open lists 1.5× cheaper per blended million tokens. Whether 12.5 points is worth that depends on how much a wrong answer costs you.
Is Muse Spark Open cheaper than SpaceXAI: Grok 4.5?
Muse Spark Open is cheaper. On a 3:1 input:output blend, Muse Spark Open lists at $2.00 per million tokens and SpaceXAI: Grok 4.5 at $3.00 — Muse Spark Open is 1.5× cheaper. Input and output are priced separately — Muse Spark Open charges $1.25 in and $4.25 out, SpaceXAI: Grok 4.5 charges $2.00 and $6.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Muse Spark Open vs SpaceXAI: Grok 4.5: which scores higher on benchmarks?
Muse Spark Open scores 57.6 and SpaceXAI: Grok 4.5 scores 70.1 overall on LiveBench, the mean of its seven categories. That is a 12.5-point lead for SpaceXAI: Grok 4.5. 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 SpaceXAI: Grok 4.5 have a bigger context window?
Muse Spark Open has the larger context window: 1.0M for Muse Spark Open against 500K for SpaceXAI: Grok 4.5. Note that a window you can fill is not a window you should fill — retrieval quality usually degrades well before the limit, and you pay for every token you put in it.
Do Muse Spark Open and SpaceXAI: Grok 4.5 support prompt caching?
Both publish a cached-input rate: $0.150 per million for Muse Spark Open and $0.300 for SpaceXAI: Grok 4.5, against full input rates of $1.25 and $2.00. 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.