Muse Spark 1.3
Solid coding and agent model at a low token price; GPT-6.1 Sol and Claude rank higher if quality matters most.
Should you use it?
Pick it if
Developers who want good coding and agent results at a low token price.
Best for: Low-cost coding and agent work through Meta's API (Chat models Top 20)
Skip it if
You want the best results per task; GPT-6.1 Sol costs only slightly more per agent task and ranks much higher.
You give up: Ranks well below GPT-6.1 Sol on agent tasks; the cheapest tier uses your data
The short version
- What this is
- Meta's closed Muse Spark model, version 1.3 released 2 Sep 2026, on the Meta Model API, OpenRouter and the Muse Code coding agent.
- Why it matters
- It is one of the cheaper models near the top of the coding and agent boards, from a maker people know.
- Rank 13 on arena.ai WebDev and 15 on the Agent board s1 s3.
- API $1.25 / $4.25 per 1M tokens; about $0.51 per arena.ai Agent task s11 s4.
- GPT-6.1 Sol ranks much higher for only a little more per agent task s3 s4.
Good at
Our take
Muse Spark 1.3 is a solid second-tier model. On 11 Oct 2026 it ranks 13th on arena.ai WebDev and 15th on the Agent board s1 s3, and it sits on the Agent board's cost-per-task frontier at $0.51 a task s4. Meta's AI chief told Axios it is "very competitive with frontier models" s10; the public boards put it a step below them.
The value case is narrower than the token price suggests. GPT-6.1 Sol costs $0.57 per Agent task, only a little more, and ranks far higher s4 s3. On the Artificial Analysis index it costs $1.60 a task at max effort, more than GPT-6.1 Sol's $0.72 s5. If you send data through the cheap contributor variant, Meta uses it to improve its products s11.
Scores by job
A score from 0 to 100 per job, against everything available today. Overall 70 across 3 jobs, the average of the job scores.
New to this? What the scores and labels mean
- 0 to 100
- Our score for one job, like writing or coding, compared with everything else out today. 100 is the best available today. For AI models we build it from public data, such as Arena's blind votes and Epoch AI's independent tests; apps and tools are scored on our own checklist. The same tool can score differently for different jobs, and where two likely ranges overlap, we call it a tie.
- Our verdict
- Use it: a top choice for most people. Worth trying: good, and worth a go. Depends: good for some people or one kind of job. Wait: too early to tell, or not out for everyone yet. Skip: something else does the job better.
- First look
- Just released. We say what it is and whether to bother, and give it a score once public results exist.
- No score yet
- None of the public sources we use covers it yet, or the only evidence is from a source whose numbers we can't use, so we describe it in words instead.
- Best buy
- Nothing cheaper scores as well for that job.
- Best free
- The best score for that job that costs nothing, through a free plan or by running on your own computer.
- Pay as you go
- No monthly plan: you pay for each use, usually through a developer account.
- Checked
- The day we last confirmed the score and the price against the sources. Prices change often, so check the date.
- AI model
- The engine underneath, like GPT or Claude. You use it through an app or, if you code, directly.
- Open source
- Free to download and run on your own computer, so nothing leaves your machine.
#5 of the 12 we have scored for this job.
From blind votes (Arena) · Arena data, CC BY 4.0
1 source so farData read 20 Oct
#12 of the 15 we have scored for this job.
From blind votes (Arena) and independent tests (Epoch AI) · Arena data, CC BY 4.0, Epoch AI data, CC BY 4.0
2 sourcesData read 20 Oct
#14 of the 21 we have scored for this job.
From blind votes (Arena) · Arena data, CC BY 4.0
1 source so farData read 20 Oct
#15 in Arena's blind votes for agents. Those votes give a rank but no rating, so there is no score yet.
#15 in Arena's blind votes for agents (rank only, no score yet) · Arena data, CC BY 4.0
2 sourcesData read 20 Oct
Alternatives
Better or cheaper for agents, from our scores, then the ones we'd also look at. The same kind of product comes first.
- Claude Opus 5.5BetterText model#1$20 a monthRanked #1 on Arena's Agent board in agents, against #15 here; $20 a month. Side by side
- MiMo-V2.6-ProCheaperText model#13FreeRanked #13 on Arena's Agent board in agents for free, against $5 a month here. Side by side
- GPT-6.1 SolText model#4$20 a monthMuch higher on Agent and WebDev for $0.57 against $0.51 per arena.ai Agent task s4. Side by side
- DeepSeek-V4.1-FlashText modelNot reviewed yetAlso on the Agent cost frontier, close on net improvement at about a quarter of the cost per task.
- Gemini 3.8 FlashText model91Writing$19.99 a monthStronger at creative writing and maths for a similar token price. Side by side
Value for money
Where it sits in agents: higher is a better score, further left is cheaper. Green dots are the Best buys.
Evidence
Everything behind the call and the scores, folded so the page stays short. Spotted a wrong price, score or link? Report a mistake.
How we scored this
The writing, research and coding scores are our own, built from public data: blind votes on Arena and, where they cover the job, Epoch AI's independent tests. How we combine them is our method and we don't publish it. For agents, Arena's blind votes give a rank but no rating, so we show the rank and no score yet.
Public leaderboardIndependent test
Reviews are drafted with help from AI models, including Anthropic's Claude. Model scores come only from outside leaderboards and independent evaluations, by a written rule.
No one paid for this review or gave us free access, and we earn nothing if you sign up. How we score
Sources 12
- s1arena.ai Code Arena: WebDev leaderboard
- s2arena.ai Text: Coding leaderboard
- s3arena.ai Agent leaderboard
- s4arena.ai Agent Pareto and cost per task
- s5Artificial Analysis LLM leaderboard
- s6arena.ai Text: Expert leaderboard
- s7arena.ai Text: Creative Writing leaderboard
- s8arena.ai Text: Instruction Following leaderboard
- s9Meta: Muse Code
- s10Axios: Meta debuts Muse Spark 1.3
- s11Meta Model API: Muse Spark
- s12arena.ai Agent Alignment Index
Something here out of date or wrong? Report a mistake and we will check it against the source.
History 2 changes
Every change to a rating, the price or our call, with the reason. Scores are against what exists on the day, so they drift down as better things ship. Older entries come from before we moved to scores.
- New: Coding ratedNew: Agents ratedNew: Research ratedNew: Writing ratedReviewed: coding, agents, research, writing.
- Audit: the $0.51 and $0.57 agent costs are the Pareto view's 14-day medians, not the main table's median ($0.52 and $0.58); citations and labels corrected. Alignment Index wording made complete. Ratings re-derived, unchanged.
Use it well 4 guides on this site
Pages on this site that help with the jobs above.