Muse Spark 1.3
Meta · released Sep 2, 2026
- Type
- Closed
- Input
- $1.25
- Output
- $4.25
- Cached
- $0.15
List price · per 1M tokens · Meta at 1M context · source ↗
Our take
Written Sep 6, 2026Muse Spark 1.3 is Meta's proprietary multimodal model that can handle up to one million tokens in a single request. It scored well on web-application coding tests and offers a very cheap direct channel, though its weights cannot be downloaded.
Pick this for long-context workflows needing one million tokens of working memory, or web-app building where it scored 1622.5 on Arena Code. Use the Meta direct channel for cost-sensitive coding work. Skip it if you need measured chat or reasoning scores, an open-weights fallback, or if you must use OpenRouter where the price is steep and throughput unverified.
The case for it
- One-million-token request limit, among the largest disclosed.
- Measured web-development coding quality at 1622.5 on Arena Code.
- Meta direct channel is dramatically cheaper than the alternative route.
The case against it
- Only one benchmark measured in our data; no chat, reasoning or general coding scores.
- Proprietary weights with no open-weights fallback and undisclosed licence terms.
- OpenRouter pricing is steep for unverified throughput.
How good is it?
A general-purpose assistant for everyday questions, drafting and coding, with tool use when a request needs it.
- getting answers to everyday questionsArena Text (overall) · 7th of 168
- drafts, rewrites and editingArena Creative Writing · 26th of 168
- writing and completing codeArena Coding · 7th of 168
- calling tools to carry out requestsArena Agent · Tool use · 9th of 55
EverydayGeneral questions and everyday reasoning
Arena Text (overall)7th of 168 · 1494
CodingWriting and fixing code on its own
Arena Coding7th of 168 · 1539
AgenticPlanning, calling tools, staying on task
Arena Agent15th of 55 · 0.039
WritingDrafting and rewriting prose
Arena Creative Writing26th of 168 · 1450
Placings on Arena's agent boards, from live sessions people ran themselves. A model can lead on one of these and sit mid-field on the others.
Boards this model appears on that none of the ratings above are built on.
Every published score for this model20 scoresEvery figure we hold, from 20 boards, with who ran it and a link to the source — including the boards no rating above is built on.
Where to rent it
Prices checked 4 hours ago — each listing carries its own date.
Meta, through OpenRouter
The lab is also the cheapest we hold. The strip above and this offer are the same one, so nothing on this page undercuts Meta on 1M of context.
- per 1M tokens
- $1.25 in / $4.25 out
- Context served
- 1M
- Throughput
- ~75 tok/s
| Provider | In / out per 1M tokens | Context | Throughput | Trains on prompts | Logs prompts | Zero retention |
|---|---|---|---|---|---|---|
| OpenRouterOpenRouter's own listing | $1.25 / $4.25checked 4 hours ago | 1M | not measured | Unknown | Unknown | Unknown |
| MetaThrough OpenRouter | $1.25 / $4.25checked 4 hours ago | 1M944K max reply | 75 tok/s | No | Yes30 days | Unknown |
OpenRouterAcross the 2 listings we hold: 1 says it does not train on prompts, 0 say they do and 1 does not say. 0 appear in the zero-retention registry we check; the rest are unknown to us.
What each host's API supports
From the parameter list each endpoint publishes. Streaming is omitted: nothing we hold reports it, for any model.
| Provider | Tool calling | JSON output | Strict schema |
|---|---|---|---|
| OpenRouterOpenRouter's own listing | ✓ | ✓ | ✓ |
| MetaThrough OpenRouter | ✓ | ✓ | ✓ |
Tool calling: 2 of 2 listings say yes. JSON output: 2 of 2 listings say yes. Strict schema: 2 of 2 listings say yes.
Models people weigh against Muse Spark 1.3
When we formed this view
Recent changes
Each date is the day we first saw the change, or the day the maker announced it.
What we do not know about this model yet
- Nothing we hold says whether an endpoint streams, so we do not show it either way.
- 1 of 2 listings does not say whether it trains on prompts.
- We hold no batch or off-peak rate for any of its listings.
Licence and identifiers
What the licence allowsWe hold no licence record for this model. Inside are the identifiers you need to pull it — its Hugging Face repo where we have one, our slug and a machine-readable card.
Licence
We hold no licence record for this model, and no record of published weights either — so we can neither summarise its terms nor point you at the weights.
Identifiers
- Takes in, gives back
- Text, images, audio, video and documents in, text out
- Catalogue slug
- meta-muse-spark-1-3