Muse Spark 1.3
Meta's Muse Spark 1.3 is a major chatbot model for writing and answering questions, offered to developers online.
Key facts
- Released
- Sep 2, 2026
- What it does
- Text and chat: Writes, answers questions and holds a conversation.Thinks first: Can reason step by step before it answers: slower, but better at maths, code and tricky questions.Sees images: Understands pictures, screenshots and charts you share with it.Reads files: Reads documents such as PDFs.Listens: Understands speech and other sounds.Watches video: Understands video clips you share with it.
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- How
- For developers, through an API
- Announced as
- “Introducing Muse Spark 1.3”
From trckr's archive of releases before it started watching. Date and details from Epoch AI's database of AI models (CC BY 4.0).
Price and limits
What developers pay to use it through the API: How developers plug a model into their own apps and pay per use. A model that's "in the API" can be used by programmers, even if it isn't in a chat app yet., per million Tokens: The small chunks of text a model reads and writes, about three-quarters of a word each. Prices and limits are counted in tokens. sent (input) or written back (output), and how much it can take in at once.
- Input
- $1.25
- per million tokensCached: $0.15
- Output
- $4.25
- per million tokens
- Context window: How much a model can keep in mind at once: your question, any files you share and its own replies. Measured in tokens; 1,000 tokens is about 750 words.
- 1.05M tokens
- about 790,000 words
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- Longest answer
- 131K tokens (about 98,000 words)
From the lab's own listing on models.dev and OpenRouter, checked .
How it scores
From independent testers, never the lab's own claims.
- Combined test score#23 of 235
- GPT-6 Astra169
- 2GPT-6.1 Sol169
- 22Gemini 3.7 Flash158
- 23Muse Spark 1.3158
- 24Grok 4.6158
Source: Epoch AI · Epoch Capabilities Index
- Chat answers, by people's votes#10 of 86
- Gemini 4 Carbon1,527
- 2Gemini 4 Argon1,522
- 9Gemini 3.8 Flash1,498
- 10Muse Spark 1.31,496
- 11Muse Spark 1.21,494
Source: LMArena · LMArena text, adjusted for style
- Building apps, by people's votes#16 of 85
- Claude Opus 5.51,818
- 2Claude Sonnet 5.51,773
- 15Kimi K31,657
- 16Muse Spark 1.31,654
- 17Muse Wonder1,650
Source: LMArena · LMArena WebDev
Compare Muse Spark 1.3 with
It came out 23 days after Muse Glimmer, the lab's previous model.
The details
Muse Spark 1.3 is Meta's text model for language generation and question answering, accessed through an API: How developers plug a model into their own apps and pay per use. A model that's "in the API" can be used by programmers, even if it isn't in a chat app yet. and not released as a download.
Model ID: The exact name developers type to use a model, like gpt-5-mini. New IDs often show up in a lab's systems before the official announcement, which is how trckr spots many releases early.
meta/muse-spark-1.3-contributorTimeline
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