STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Claude Haiku 5.5 vs Muse Spark Open

Claude Haiku 5.5 leads Muse Spark Open by 5.4 points on StealthMark, 49.5 to 44.1. It leads on 6 of 9 benchmarks, including both games, and Muse Spark Open on 3. Claude Haiku 5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

49.5/100Overall rank 17/53
44.1/100Overall rank 29/53

General Intelligence

47.6/100
42.6/100

Visual Intelligence

52.8/100
46.6/100

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

  • Claude Haiku 5.5
  • Muse Spark Open

Open or local

BENCHMARK BY BENCHMARK

Where each model leads

  • Claude Haiku 5.5
  • Muse Spark Open
  • Other models
  • Median

DATASHEET

Specs and pricing

Claude Haiku 5.5 scores higher on StealthMark, is 8.5× cheaper per output token and runs 11% faster in our speed test. Both take about 1M tokens of context.

  • Claude Haiku 5.5
  • Muse Spark Open
  • Other models
  • Median
PricePer 1M output tokens, input below
Claude Haiku 5.5: $0.508.5× cheaper$0.10 inputMuse Spark Open: $4.25$1.25 input
Context windowTokens per request, max output below
Claude Haiku 5.5: 1MTied128K max outputMuse Spark Open: 1MTied1M max output
Output speedTokens per second, our measurement
Claude Haiku 5.5: 40211% fastertokens/sMuse Spark Open: 361tokens/s
SizeTotal and active parameters
Claude Haiku 5.5: Not disclosedMuse Spark Open: 816B42B active
Developer
AnthropicMeta
Released
7 Oct 202615 Oct 2026
Origin
United StatesBoth
Input → output
Text, image → textText, image, audio, video → text
Architecture
Not publishedSparse 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.

Full datasheets, every price and sourceClaude Haiku 5.5 ↗Muse Spark Open ↗

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.

Claude Haiku 5.5 34.4/100Rank 25/47

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

Muse Spark Open 29.4/100Rank 34/47

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

Points per level

LevelClaude Haiku 5.5Muse Spark Open
Level 1Second Thoughts
4 ptsOut of lives
4 ptsOut of lives
Level 2Pressure Pot
7 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
9 ptsSurvived
8 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.

Claude Haiku 5.5 78.3/100Rank 10/48

Cleared 5 of 5
Latch: complete playing field
Level 520.6 ptsTurn 27 / 40

Muse Spark Open 75.7/100Rank 12/48

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

Points per level

LevelClaude Haiku 5.5Muse Spark Open
Level 1Hold the door
5 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.8 ptsCleared
Level 3Relay vault
18.8 ptsCleared
19.2 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
17.8 ptsClearedFinished early · 1 beacon left
Level 5Second thoughts
20.6 ptsCleared
19.6 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

Claude Haiku 5.5

The centered sphere, compact airborne black blob and differentiated cyan/crimson interaction support substantial state and placement credit. The few recognizable sphere and panel images establish limited optical relationships, but most of the required mirror system is missing. Rounded volume and localized paint warrant substantial material credit despite the soft, illustrative finish.

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.

Score breakdown

CategoryClaude Haiku 5.5Muse Spark Open
State at 600 ms25.0/2514.0/25
Camera and placement8.0/156.0/15
Reflections24.5/1208.0/120
Materials and scale7.5/103.5/10
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

Claude Haiku 5.5

A coherent coral squid emblem with a compact mantle, restrained face and clean centered presentation. Its radial silhouette and floating placement work, but sharp arm tips, crowded roots and sparse surface modeling limit softness, construction and finish.

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.

Score breakdown

CategoryClaude Haiku 5.5Muse Spark Open
Task & likeness6.5/105.0/10
Anatomy & construction4.0/104.5/10
Space & placement6.5/106.0/10
Light & reflections4.0/105.0/10
Purposeful detail3.5/106.0/10
Artistry & character3.5/105.0/10
Materials & effects4.5/105.0/10
Visual integrity7.0/106.5/10

Benchmark task

Claude Haiku 5.5

A coral squid with spreading arms tests connected anatomy, balanced composition and soft surface shading.

Muse Spark Open

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

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

Claude Haiku 5.5

A recognizable but basic Mona Lisa reinterpretation. Clean contours and smooth facial lighting provide coherence and volume. Replication remains limited by the frontal pose, elongated neck, schematic expression, unresolved crossed hands and sparse landscape. Lighting is more successful than anatomical construction and purposeful detail.

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.

Score breakdown

CategoryClaude Haiku 5.5Muse Spark Open
Task & likeness3.0/103.0/10
Anatomy & construction4.0/103.0/10
Space & placement4.0/105.0/10
Light & reflections5.5/104.5/10
Purposeful detail2.5/104.0/10
Artistry & character3.5/103.0/10
Materials & effects2.5/104.0/10
Visual integrity5.5/106.0/10

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

Claude Haiku 5.5

A cheerful, coherent beach illustration with attractive sunset colors, readable accessories and clean silhouettes. Its sun and sailboat reflections establish useful physical relationships. Simple animal construction, flattened foreground placement, sparse directional shadows and minimally differentiated surfaces limit its drawing refinement.

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.

Score breakdown

CategoryClaude Haiku 5.5Muse Spark Open
Task & likeness8.5/108.0/10
Anatomy & construction6.5/106.0/10
Space & placement7.0/106.5/10
Light & reflections7.0/105.5/10
Purposeful detail7.0/106.5/10
Artistry & character6.0/105.5/10
Materials & effects6.0/106.0/10
Visual integrity8.5/108.0/10

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

Claude Haiku 5.5

This benchmark has not been assessed yet.

Muse Spark Open

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

Claude Haiku 5.5

A tidy, appealing cartoon with recognizable animals and a pleasing sunset palette. Steering lacks visible controls, while schematic limbs and uncertain raccoon support weaken the requested interaction. Shallow vehicle construction, flat character lighting and modest displacement limit physical coherence. Clean shapes and readable identifying details remain strengths.

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.

Score breakdown

CategoryClaude Haiku 5.5Muse Spark Open
Task & likeness4.0/104.0/10
Anatomy & construction3.5/103.0/10
Space & placement5.5/106.0/10
Light & reflections4.0/104.5/10
Purposeful detail5.5/107.0/10
Artistry & character4.5/103.5/10
Materials & effects5.5/105.0/10
Visual integrity4.5/105.0/10

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

Claude Haiku 5.5

A cheerful, recognizable illustration with clean contours and a balanced warm palette. Aligned wheels and readable frame geometry establish the bicycle, but shoulder construction, feet and steering contact remain imprecise. Sparse drivetrain detail, flat materials and absent grounding shadows limit anatomical and spatial conviction.

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.

Score breakdown

CategoryClaude Haiku 5.5Muse Spark Open
Task & likeness8.0/107.5/10
Anatomy & construction5.5/105.0/10
Space & placement6.5/106.0/10
Light & reflections5.0/105.0/10
Purposeful detail6.0/106.5/10
Artistry & character5.0/105.5/10
Materials & effects5.0/106.0/10
Visual integrity8.0/107.5/10

Benchmark task

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