MetaUnited States· released Jul 2026

Muse Spark 1.1

Name: Muse Spark 1.1
Author: Meta

Provisional: 9 comparable tests so far. Ranked once it reaches 6 across 3 counting categories.

Meta, United States. One of 4 models from this lab on the Index.

Third-party publishedLow confidence (thin coverage)

Snapshot September 8, 2026

OpenCharts Index

71.3

Provisional: not enough comparable tests or counting categories to rank yet · 9 comparable tests · 0 counting categories

Drop any single test and the Index lands between 67.3 and 76.7.

Needs more results (0 of 8 so far)

Distance to today's frontier on the hardest tests. Not a measure of intelligence.

What it's known for

Muse Spark 1.1, in 9 results.

Its widest gap is on Code Arena (WebDev), 62.7% behind the best published result. No comparable result yet in long context. Between 25% and 30% behind the best published results, on average.

Strongest category

No category counts yet: a category counts once it has more than one comparable test and the model has taken at least half of them. The scores it has are below.

Best single result

Text Arena

Answer the same prompt as a rival model; real users vote blind on which answer they prefer.

1,492

48% expected win rate against the board leader (1,507) · #8 of 92.

Millions of blind votes on real prompts are the market's measure of what people prefer.

Where it trails

Code Arena (WebDev)

Build a web app from the same prompt as a rival model; real users vote blind on the result.

1,541

62.7 points short of parity with the board leader (1,797) · #23 of 86.

People judging finished apps side by side is the most honest measure of front-end quality.

Not measured yet

No comparable result yet in this category. A blank is a blank, never a zero, and it does not lower the Index.

Long context

Covered, but not averaged into the Index:

Reasoning1 of 6 tests · needs 3 · mean 46.7
Knowledgesingle-test category, shown beside the Index · 76.4
Coding2 of 7 tests · needs 4 · mean 65.6
Math1 of 5 tests · needs 3 · mean 39.0
Agentic2 of 8 tests · needs 4 · mean 85.5
Multimodalsingle-test category, shown beside the Index · 90.4
Human preferencesingle-test category, shown beside the Index · 95.7

Every score, with its source

See it at work

What Muse Spark 1.1 was asked to do, and how it did.

Every test it has taken, by category, with the kind of task it faced, who produced the number and where the result landed against the best published one. The examples are original and illustrative, never items from the datasets themselves.

Human preference · mean 95.7 across 1 comparable test · a single-test category, shown beside the Index and never averaged into it

Text ArenaLeaderboard

Answer the same prompt as a rival model; real users vote blind on which answer they prefer.

1,492

48% expected win rate against the board leader (1,507)
#8 of 92

board 2026-09-02

Source: Arena

Every result is read against the best published one on its test: percent scores as a share of the best above chance, Arena ratings as the expected win rate against the board leader, open-ended values on a log scale. Sitting a harder exam never lowers a model. Every number links to the publisher that produced it.

Head to head

Muse Spark 1.1 against whoever you pick.

Choose a rival. Every counted test both have taken appears side by side as a share of the best published result on that test, with the category means above. A win is a higher share; a gap under 2 points is a tie, because one item on a 45-problem exam is 2.2 points and publishers' own standard errors are of that order.

Muse Spark 1.1

provisional·Index 71.3B-

1 : 5

wins · 0 ties · 6 shared

GPT-6 Astra

#1·Index 99.0A+

GPT-6 Astra comes out ahead on 5 of the 6 tests both have taken.

Category means

Reasoning
46.7
99.6
Knowledge
76.4
100.0
Coding
65.6
97.7
Math
39.0
99.8
Agentic
85.5
98.5
Multimodal
90.4
—
Human preference
95.7
—

Shared tests · biggest gaps first

Code Arena (WebDev)Coding
1,541
1,797
−62.7
ProofBenchMath
39.0%
99.0%
−60.0
CritPtReasoning
15.1%
31.7%
−51.5
SimpleQA VerifiedKnowledge
57.8%
75.6%
−23.6
APEX-AgentsAgentic
41.9%
46.7%
−10.1
SciCodeCoding
58.2%
56.5%
+2.8

Bars are distances to the best published result on each test (percent scores above chance, Arena ratings as win rate against the leader, open-ended values on a log scale). Raw values as the publishers report them.

Open GPT-6 Astra

Scores

Every test, every source

The best published run per benchmark, the raw value as the publisher reports it, who produced the number, how close it comes to the best published result on that test, and where the model sits among every model scored on it. Percent scores are read above chance, Arena ratings as a win rate against the board leader, open-ended values on a log scale. A test with too few models to compare against is shown but not counted.

Category means

Reasoning46.7 · 1/6
Knowledgebeside76.4 · 1/1
Coding65.6 · 2/7
Math39.0 · 1/5
Agentic85.5 · 2/8
Multimodalbeside90.4 · 1/1
Human preferencebeside95.7 · 1/1
Long context—

Mean · tests taken of the category's comparable tests. A faded category either rests on fewer than half of them or is a single-test category (marked “beside”), which is shown next to the Index and never averaged into it.

CritPtLeaderboardReasoning

15.1%

46.7% of the best (32.3%)
66th percentile of 78

Source: Epoch AI — AI Benchmarking Hub

SimpleQA VerifiedEpoch-runKnowledge

57.8%

76.4% of the best (75.6%)
79th percentile of 57 · n = 1,000

Source: Epoch AI — AI Benchmarking Hub

SciCodeLeaderboardCoding

58.2%

93.8% of the best (62.0%)
94th percentile of 73 · n = 338

Source: Epoch AI — AI Benchmarking Hub