STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Beam 1.0 501B A23B vs Muse Spark 1.3

Muse Spark 1.3 leads Beam 1.0 501B A23B by 7.9 points on StealthMark, 39.8 to 31.9. It leads on 7 of 9 benchmarks, including both games, and Beam 1.0 501B A23B on 2. Beam 1.0 501B A23B scores higher on Newton's Mirror, with its largest category advantage in state at 600 ms.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

31.9/100Overall rank 42/53
39.8/100Overall rank 34/53

General Intelligence

30.9/100
38.3/100

Visual Intelligence

33.8/100
42.3/100

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

Open or local

Open modelApache 2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • Beam 1.0 501B A23B
  • Muse Spark 1.3
  • Other models
  • Median

DATASHEET

Specs and pricing

Beam 1.0 501B A23B is 4.3× cheaper per output token and runs 3× faster in our speed test. Muse Spark 1.3 scores higher on StealthMark. Both take about 1M tokens of context.

  • Beam 1.0 501B A23B
  • Muse Spark 1.3
  • Other models
  • Median
PricePer 1M output tokens, input below
Beam 1.0 501B A23B: $14.3× cheaper$0.25 inputMuse Spark 1.3: $4.25$1.25 input
Context windowTokens per request, max output below
Beam 1.0 501B A23B: 1MTied128K max outputMuse Spark 1.3: 1MTied
Output speedTokens per second, our measurement
Beam 1.0 501B A23B: 9723× fastertokens/sMuse Spark 1.3: 321tokens/s
SizeTotal and active parameters
Beam 1.0 501B A23B: 501B23.4B activeMuse Spark 1.3: Not disclosed
Developer
Reflection AIMeta
Released
16 Oct 20262 Sep 2026
Origin
United StatesBoth
Input → output
Text → textText, image, video, audio, PDF → text
Architecture
Sparse mixture-of-experts transformer; 52 layers (3 dense, 49 MoE), 256 experts with 8 selected per token; gated GQA and sliding-window attentionNot published

Full datasheets, every price and sourceBeam 1.0 501B A23B ↗Muse Spark 1.3 ↗

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.

Beam 1.0 501B A23B 49.4/100Rank 18/47

Survived 1 of 3
Foresight: complete playing field
Level 39 ptsTurn 20 / 20

Muse Spark 1.3 64.3/100Rank 6/47

Survived 2 of 3
Foresight: complete playing field
Level 311 ptsTurn 17 / 20

Points per level

LevelBeam 1.0 501B A23BMuse Spark 1.3
Level 1Second Thoughts
18 ptsOut of lives
26 ptsSurvived
Level 2Pressure Pot
9 ptsOut of lives
10 ptsSurvived
Level 3Hide or Flight
9 ptsSurvived
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.

Beam 1.0 501B A23B 37.3/100Rank 29/48

Cleared 2 of 5
Latch: complete playing field
Level 55 ptsTurn 30 / 40

Muse Spark 1.3 72.4/100Rank 26/483 of 5 levels

3 of 5 played
Latch: complete playing field
Level 318.8 ptsTurn 32 / 36

Points per level

LevelBeam 1.0 501B A23BMuse Spark 1.3
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.6 ptsCleared
9.8 ptsCleared
Level 3Relay vault
11.2 ptsFinished early
18.8 ptsCleared
Level 4Passing bay
3.6 ptsFinished early
Pending
Level 5Second thoughts
5 ptsFinished early
Not played

Newton's Mirror

Same task instructions

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

The judgment

Beam 1.0 501B A23B

Central object placement is fairly close, but the defining mirrored-room structure is missing. The paint colors suggest the required contact order without establishing their different interaction histories. The faint floor oval does not demonstrate valid reflection geometry, so it earns no reflection credit. Rounded volume and glossy paint provide limited material credit despite weak metallic finishes and oversized paint bodies.

Muse Spark 1.3

The paint state is incorrectly and poorly drawn, despite a recognizable sphere-and-paint setup. The oversized sphere, oversized compact paint bodies, and blurred wall and floor images further limit the result. Isolated reflection cues provide very little support for the required repeated virtual rooms, nested spherical imagery or emitter mapping.

Score breakdown

CategoryBeam 1.0 501B A23BMuse Spark 1.3
State at 600 ms20.5/256.0/25
Camera and placement11.5/158.5/15
Reflections2.0/1205.5/120
Materials and scale3.0/104.0/10
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

Beam 1.0 501B A23B

An appealing expression and warm palette support a coherent simple cartoon. The central polishing joke is not legible: the cloth is unresolved and the nose sits away from the fan. Pointed radial plates, uncertain limb attachments and weak ground contact limit construction, while restrained surface detail limits material richness.

Muse Spark 1.3

The luminous creature and geometric mirror counterpart communicate self-recognition through a coherent palette and expressive eyes. The transformed reflection is purposeful. Simple oval anatomy, ambiguous reaching-arm construction, shallow spatial staging and limited illumination of nearby surfaces keep the illustration below exceptional execution.

Score breakdown

CategoryBeam 1.0 501B A23BMuse Spark 1.3
Task & likeness4.0/108.0/10
Anatomy & construction3.5/105.0/10
Space & placement5.5/106.5/10
Light & reflections5.5/107.0/10
Purposeful detail4.5/106.5/10
Artistry & character4.0/105.5/10
Materials & effects4.5/106.5/10
Visual integrity7.0/107.5/10

Benchmark task

Beam 1.0 501B A23B

A golden pangolin polishes its oversized amber tail while its nose smudges the same scale. The scene tests expressive anatomy, physical contact and contrasting translucent, polished and soft materials.

Muse Spark 1.3

An imagined creature encounters its reflection. The scene tests original character design, visual self-interpretation and the relationship between a subject and its reflected image.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

Beam 1.0 501B A23B

The candidate shows a faint warm oval against an almost entirely black field. Minimal placement and smooth tonal variation are visible, but the portrait, anatomy, crossed hands and landscape remain unreadable. The saved comparisons provide no specific evidence supporting a change to the baseline categories.

Muse Spark 1.3

Dark hair, a restrained smile and overlapping hands suggest Mona Lisa, but replication is weak. The face is markedly elongated, the hands are oval pads with faint finger strokes, and the atmospheric landscape is absent. Soft gradients provide basic volume, while the frontal symmetry, shallow space and sparse clothing detail limit the portrait’s drawing quality.

Score breakdown

CategoryBeam 1.0 501B A23BMuse Spark 1.3
Task & likeness0.0/101.0/10
Anatomy & construction0.0/101.5/10
Space & placement0.0/101.5/10
Light & reflections0.5/101.5/10
Purposeful detail0.0/101.0/10
Artistry & character0.0/101.5/10
Materials & effects0.0/101.5/10
Visual integrity0.0/103.0/10

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

Beam 1.0 501B A23B

A coherent, cheerful beach illustration fulfills the main subjects with clean shapes and a strong sunset focal point. Its basic geometric construction, ambiguous animal anatomy, shallow depth and schematic lighting limit its accomplishment. Decorative details provide interest without developing intricate forms or convincing physical surfaces.

Muse Spark 1.3

The warm sunset, framing palms and colorful beach accessories create an appealing scene with the requested animals, birds and reflections. Construction remains schematic: the raised hand misses the kite string, and a doglike silhouette hangs above the water without clear support. The sun reflection establishes a focal path, but shadows and materials lack depth. An unexplained horizontal bar crosses the sun.

Score breakdown

CategoryBeam 1.0 501B A23BMuse Spark 1.3
Task & likeness7.0/106.5/10
Anatomy & construction5.0/103.0/10
Space & placement6.0/105.5/10
Light & reflections5.0/106.5/10
Purposeful detail5.5/105.0/10
Artistry & character4.0/103.5/10
Materials & effects5.0/103.0/10
Visual integrity5.0/103.5/10

Benchmark task

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

Ground Truth

Different task instructions

Physical reasoning, light and visual reconstruction.

The judgment

Beam 1.0 501B A23B

This benchmark has not been assessed yet.

Muse Spark 1.3

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

Beam 1.0 501B A23B

A cheerful, readable illustration with recognizable animals, expressive faces and useful accessories. Simple rounded construction limits complexity, while ambiguous steering attachments and weak hull-to-water contact reduce physical coherence. Lighting and surface effects establish the setting without convincing environmental interaction.

Muse Spark 1.3

The raccoon clearly rides on the dog's back, and the dog's paws reach the jet ski controls. Expressive faces and bright colors make the scene appealing. Simplified joints, crowded steering geometry and shallow hull perspective limit construction. The sun has no corresponding water reflection, and the splash shapes convey speed more clearly than convincing displacement.

Score breakdown

CategoryBeam 1.0 501B A23BMuse Spark 1.3
Task & likeness5.0/108.5/10
Anatomy & construction3.5/106.5/10
Space & placement5.5/107.0/10
Light & reflections4.0/105.0/10
Purposeful detail6.5/106.5/10
Artistry & character3.5/105.5/10
Materials & effects5.0/106.0/10
Visual integrity6.5/107.5/10

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

Beam 1.0 501B A23B

A cheerful, clearly readable pelican-and-bicycle illustration with clean contours and balanced composition. Simple geometric construction limits artistic complexity, while ambiguous neck and steering overlaps, merged pedal contacts and an incomplete drivetrain weaken physical coherence.

Muse Spark 1.3

The pelican and bicycle are immediately recognizable, with an expressive face, bold bill and cheerful composition. Both legs connect to the body and reach pedal-like supports, but articulation, saddle support and wing contact with the handlebar remain unclear. Wheel alignment and layering are coherent. Simple landscape shapes, generic shadows and limited material variation constrain the finish.

Score breakdown

CategoryBeam 1.0 501B A23BMuse Spark 1.3
Task & likeness5.5/108.5/10
Anatomy & construction4.5/106.0/10
Space & placement5.0/107.0/10
Light & reflections4.0/106.0/10
Purposeful detail4.0/107.0/10
Artistry & character4.0/105.5/10
Materials & effects4.0/106.5/10
Visual integrity5.5/107.0/10

Benchmark task

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