STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Muse Spark Open vs Qwen3.8-27B

Qwen3.8-27B leads Muse Spark Open by 7.6 points on StealthMark, 51.7 to 44.1. It leads on 7 of 9 benchmarks, including Foresight, and Muse Spark Open on 2, including Latch. Qwen3.8-27B scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

44.1/100Overall rank 29/53
51.7/100Overall rank 14/53

General Intelligence

42.6/100
46.2/100

Visual Intelligence

46.6/100
61.4/100

Reasoning efficiency

On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.

Single-step reasoning Result quality weighed against reasoning tokens on a single problem

Multi-step reasoning Result quality weighed against reasoning tokens across connected steps, as in agentic workflows

  • Muse Spark Open

Open or local

Local modelOpen model · Apache-2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • Muse Spark Open
  • Qwen3.8-27B
  • Other models
  • Median

DATASHEET

Specs and pricing

Muse Spark Open runs 4.6× faster in our speed test. Qwen3.8-27B scores higher on StealthMark and is 2.5× cheaper per output token. Both take about 1M tokens of context.

  • Muse Spark Open
  • Qwen3.8-27B
  • Other models
  • Median
PricePer 1M output tokens, input below
Muse Spark Open: $4.25$1.25 inputQwen3.8-27B: $1.702.5× cheaper$0.42 input
Context windowTokens per request, max output below
Muse Spark Open: 1MTied1M max outputQwen3.8-27B: 1MTied128K max output
Output speedTokens per second, our measurement
Muse Spark Open: 3614.6× fastertokens/sQwen3.8-27B: 78tokens/s
SizeTotal and active parameters
Muse Spark Open: 816B42B activeQwen3.8-27B: 27BAll activeEstimated
Developer
MetaQwen
Released
15 Oct 202614 Aug 2026
Origin
United StatesChina
Input → output
Text, image, audio, video → textText, image, video → text
Architecture
Sparse mixture-of-experts Transformer with perception encoders; 62 decoder layers, 256 experts with 8 selected per token, grouped-query attention and sliding-window/full-attention layers.Dense causal language model with vision encoder; hybrid Gated DeltaNet and gated attention; MTP-trained

Full datasheets, every price and sourceMuse Spark Open ↗Qwen3.8-27B ↗

Anticipating threats and planning ahead. Collect coins while avoiding ghosts. Ghosts move before the player each turn, and collisions cost a life. 3 levels in sequence, up to 66 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

Muse Spark Open 29.4/100Rank 34/47

Survived 0 of 3
Foresight: complete playing field
Level 38 ptsTurn 15 / 20

Qwen3.8-27B 63.0/100Rank 7/47

Survived 1 of 3
Foresight: complete playing field
Level 311 ptsTurn 16 / 20

Points per level

LevelMuse Spark OpenQwen3.8-27B
Level 1Second Thoughts
4 ptsOut of lives
26 ptsSurvived
Level 2Pressure Pot
9 ptsOut of lives
12 ptsOut of lives
Level 3Hide or Flight
8 ptsOut of lives
11 ptsOut of lives

Cooperative planning and learning from experience. Coordinate two robots to push numbered cores onto matching sockets. Pressure plates hold doors open; moving either robot uses one turn. 5 levels in sequence, up to 152 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

Muse Spark Open 75.7/100Rank 12/48

Cleared 5 of 5
Latch: complete playing field
Level 519.6 ptsTurn 32 / 40

Qwen3.8-27B 38.6/100Rank 28/48

Cleared 2 of 5
Latch: complete playing field
Level 515.8 ptsTurn 31 / 40

Points per level

LevelMuse Spark OpenQwen3.8-27B
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.8 ptsCleared
Level 3Relay vault
19.2 ptsCleared
11.2 ptsFinished early
Level 4Passing bay
17.8 ptsClearedFinished early · 1 beacon left
13.2 ptsFinished early
Level 5Second thoughts
19.6 ptsCleared
15.8 ptsFinished early

Newton's Mirror

Same task instructions

Physics, perspective and recursive reflections, tested together. Explore the test ↗

The judgment

Muse Spark Open

The airborne black blob and deformed paint support the broad contact sequence, although cyan attachment and wheel-directed transport remain partial. The sphere and black blob have substantial framing errors. The dominant limitation is the largely absent mirror system: faint wall circles and isolated highlights provide little evidence of recursive room geometry or curved nested reflections. Oversized compact paint features and diffuse material treatment further limit credit.

Qwen3.8-27B

The room fills the complete 16:9 frame without visible borders or labels. Central placement fits the wider frame, and the paint colors follow the expected vertical order. Bilateral side images, diminishing echoes and an overlapping floor image provide limited mirror depth. Broad sphere surfaces lack ordered nested room imagery, while planar panel sequences and outer chains remain missing or unresolved. Soft highlights do not establish emitter mapping, while paint attachment and transport history are only partly supported.

Score breakdown

CategoryMuse Spark OpenQwen3.8-27B
State at 600 ms14.0/2523.0/25
Camera and placement6.0/1513.0/15
Reflections8.0/12024.0/120
Materials and scale3.5/106.5/10
Floor-damage reward0.0/100.0/10

Benchmark task

A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.

Selfie

Different task instructions

Visual construction and creative interpretation.

The judgment

Muse Spark Open

The rounded silhouette and asymmetric expression make an appealing baby elephant, supported by a quiet background and grounding shadow. The protective action remains difficult to read: forefeet cannot be confidently traced into a grip, and seed contact is crowded by fine lines. Controlled simple shapes provide charm, but limited anatomical clarity, shading and surface detail leave the execution uneven.

Qwen3.8-27B

A cohesive emerald-and-gold illustration with a gentle expression, flowing robes, luminous halo and three clearly ringed orbs. Limbs remain connected, and the asymmetric legs communicate floating. The rounded face reads somewhat bear-like; the raised palm faces outward rather than upward, and chest-hand fingers are crowded. Clean ornamentation exceeds the comparatively simple anatomical modeling and shading.

Score breakdown

CategoryMuse Spark OpenQwen3.8-27B
Task & likeness5.0/108.0/10
Anatomy & construction4.5/107.5/10
Space & placement6.0/108.0/10
Light & reflections5.0/107.5/10
Purposeful detail6.0/108.0/10
Artistry & character5.0/107.5/10
Materials & effects5.0/107.5/10
Visual integrity6.5/108.5/10

Benchmark task

Muse Spark Open

A small elephant protecting a delicate seed tests expressive anatomy, physical contact and contrasting organic materials.

Qwen3.8-27B

A floating capybara in ornate robes tests character anatomy, layered fabric and the placement of surrounding luminous forms.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

Muse Spark Open

A recognizable, orderly interpretation with clean major contours, connected body forms and modest facial shading. Wide eyes, frontal symmetry and schematic hands limit likeness and expression. Layered scenery establishes basic depth, but shallow arm overlaps, flat clothing and sparse fine detail keep the execution basic and uneven.

Qwen3.8-27B

The centered portrait, dark clothing and overlapping hands evoke the Mona Lisa, but replication is weak. The face is excessively elongated, the eyes stare broadly, and the hands reduce to rounded masses with shallow finger marks. Soft shading creates some volume, while the landscape remains indistinct. The precise gold frame is more resolved than the portrait.

Score breakdown

CategoryMuse Spark OpenQwen3.8-27B
Task & likeness3.0/104.0/10
Anatomy & construction3.0/104.5/10
Space & placement5.0/104.5/10
Light & reflections4.5/105.0/10
Purposeful detail4.0/105.0/10
Artistry & character3.0/105.0/10
Materials & effects4.0/105.0/10
Visual integrity6.0/105.0/10

Benchmark task

An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.

Beach

Different task instructions

Creativity, perspective and visual beauty.

The judgment

Muse Spark Open

A coherent sunset beach with readable activities, balanced framing and controlled colour transitions. Small accessories add interest, but schematic anatomy, limited surface detail, weak directional shadows and a geometric reflection constrain its finish. Most shapes and overlaps remain clean.

Qwen3.8-27B

The sweeping palm, glowing sunset and purple-to-orange palette create an appealing beach composition. Birds, animals and reflections fulfill the brief, with clean silhouettes and readable small accents. Schematic anatomy, repetitive shoreline geometry and limited perspective integration constrain depth. Foreground lighting and uniform reflection bars provide atmosphere but little physical coherence.

Score breakdown

CategoryMuse Spark OpenQwen3.8-27B
Task & likeness8.0/108.5/10
Anatomy & construction6.0/106.5/10
Space & placement6.5/106.0/10
Light & reflections5.5/106.0/10
Purposeful detail6.5/107.0/10
Artistry & character5.5/107.0/10
Materials & effects6.0/106.5/10
Visual integrity8.0/107.0/10

Benchmark task

A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.

Ground Truth

Same task instructions

Physical reasoning, light and visual reconstruction.

The judgment

Muse Spark Open

This benchmark has not been assessed yet.

Qwen3.8-27B

This benchmark has not been assessed yet.

Benchmark task

A plank, computer mouse and blueberry in a steel room test physical stability, spatial relationships, materials and lighting.

Raccoon

Different task instructions

Scene composition and interacting subjects.

The judgment

Muse Spark Open

Expressive faces, distinct accessories and clean color separation make the scene appealing and recognizable. Character detail is stronger than the functional construction: steering contact, limb overlaps and seating remain ambiguous. The readable hull and lively spray establish motion, while limited directional shading and simplified surfaces constrain depth and physical coherence.

Qwen3.8-27B

The raccoon clearly rides on the dog's back, and the dog reaches the jet ski's steering grip. Cheerful expressions, a bright palette and sweeping wake make the action readable. Anatomy and machinery remain simplified, with overlapping paws and limited seat definition. Flat lighting, sparse surface detail and broad white splash shapes limit depth and finish. A clipped gray fragment interrupts the upper-left corner.

Score breakdown

CategoryMuse Spark OpenQwen3.8-27B
Task & likeness4.0/108.5/10
Anatomy & construction3.0/106.5/10
Space & placement6.0/107.0/10
Light & reflections4.5/105.5/10
Purposeful detail7.0/106.5/10
Artistry & character3.5/106.5/10
Materials & effects5.0/106.5/10
Visual integrity5.0/107.5/10

Benchmark task

A jet-ski scene pairs a canine driver with a raccoon passenger. It tests the placement and contact of interacting subjects, along with vehicle construction.

Pelican

Different task instructions

Subject construction and spatial relationships.

The judgment

Muse Spark Open

A controlled, appealing cartoon with a recognizable pelican, expressive face and clean curved forms. Feather lines, spokes and bill shading provide useful complexity. Aligned wheels and a ground shadow establish placement, but uncertain pedal contacts and obscured mechanical connections weaken support and riding action. Lighting remains loosely coordinated with the sun.

Qwen3.8-27B

The pelican’s oversized bill, straw hat and flowing scarf create a distinctive focal character against a well-composed coastal sunset. Wheels and frame are readable, but the wings do not reach the steering, overlapping legs obscure separate pedal contacts, and the crank linkage is unclear. Clean vector shapes and restrained shading support an appealing illustration with limited physical depth.

Score breakdown

CategoryMuse Spark OpenQwen3.8-27B
Task & likeness7.5/108.0/10
Anatomy & construction5.0/105.5/10
Space & placement6.0/107.0/10
Light & reflections5.0/107.0/10
Purposeful detail6.5/107.5/10
Artistry & character5.5/107.5/10
Materials & effects6.0/106.5/10
Visual integrity7.5/108.0/10

Benchmark task

A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.