STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Claude Sonnet 5.5 vs MiMo-V2.6-Pro

Claude Sonnet 5.5 leads MiMo-V2.6-Pro by 22.3 points on StealthMark, 70.2 to 47.9. It leads on all 9 benchmarks. Claude Sonnet 5.5 scores higher on Ground Truth.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

70.2/100Overall rank 3/53
47.9/100Overall rank 21/53

General Intelligence

67.0/100
44.3/100

Visual Intelligence

76.1/100
54.3/100

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

  • Claude Sonnet 5.5

Open or local

Open modelMIT

BENCHMARK BY BENCHMARK

Where each model leads

  • Claude Sonnet 5.5
  • MiMo-V2.6-Pro
  • Other models
  • Median

DATASHEET

Specs and pricing

Claude Sonnet 5.5 scores higher on StealthMark and runs 2.2× faster in our speed test. MiMo-V2.6-Pro is 11× cheaper per output token. Both take about 1M tokens of context.

  • Claude Sonnet 5.5
  • MiMo-V2.6-Pro
  • Other models
  • Median
PricePer 1M output tokens, input below
Claude Sonnet 5.5: $10$2 inputMiMo-V2.6-Pro: $0.8711× cheaper$0.43 input
Context windowTokens per request, max output below
Claude Sonnet 5.5: 1MTied128K max outputMiMo-V2.6-Pro: 1MTied128K max output
Output speedTokens per second, our measurement
Claude Sonnet 5.5: 2492.2× fastertokens/sMiMo-V2.6-Pro: 116tokens/s
SizeTotal and active parameters
Claude Sonnet 5.5: Not disclosedMiMo-V2.6-Pro: 1.02T42B active
Developer
AnthropicXiaomi
Released
28 Sep 202621 Sep 2026
Origin
United StatesChina
Input → output
Text, image → textText, image, video, audio → text
Architecture
Not publishedSparse Mixture-of-Experts; OpenRouter maps the route to the released Pro-RL checkpoint. The UltraSpeed edition is a separate route

Full datasheets, every price and sourceClaude Sonnet 5.5 ↗MiMo-V2.6-Pro ↗

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 Sonnet 5.5 59.6/100Rank 11/47

Survived 2 of 3
Foresight: complete playing field
Level 310 ptsTurn 20 / 20

MiMo-V2.6-Pro 54.6/100Rank 13/47

Survived 1 of 3
Foresight: complete playing field
Level 319 ptsTurn 20 / 20

Points per level

LevelClaude Sonnet 5.5MiMo-V2.6-Pro
Level 1Second Thoughts
25 ptsSurvived
4 ptsOut of lives
Level 2Pressure Pot
10 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
10 ptsSurvived
19 ptsSurvived

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 Sonnet 5.5 83.9/100Rank 4/48

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

MiMo-V2.6-Pro 52.6/100Rank 22/48

Cleared 5 of 5
Latch: complete playing field
Level 520.4 ptsTurn 28 / 40

Points per level

LevelClaude Sonnet 5.5MiMo-V2.6-Pro
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10 ptsClearedFinished early · 1 beacon left
9 ptsClearedFinished early · 1 beacon left
Level 3Relay vault
19.2 ptsCleared
17.2 ptsClearedFinished early · 1 beacon left
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
16 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
20.6 ptsCleared
20.4 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

Claude Sonnet 5.5

The near-field silhouettes, broad perspective and paint contact order are recognizable. Missing outer chains, truncated repetitions and absent ordered imagery within the main and reflected spheres substantially limit the reflection system. Sparse spherical highlights leave much of the curved room and emitter mapping unsupported, despite some plausible planar light sequences.

MiMo-V2.6-Pro

The main framing and visible paint-contact story are well supported. Major optical omissions dominate the result: sparse repetitions, undersized first images, missing outer chains and absent curved nested imagery prevent a coherent mirror-room system. The metallic forms remain convincing in volume but have a soft illustrative finish.

Score breakdown

CategoryClaude Sonnet 5.5MiMo-V2.6-Pro
State at 600 ms24.0/2523.0/25
Camera and placement15.0/1512.0/15
Reflections35.0/12019.0/120
Materials and scale10.0/107.5/10
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 Sonnet 5.5

The centered coral squid has a friendly, composed expression and a balanced flower-like silhouette. Eight thick arms and two slender tentacles remain visibly connected, with no inverted parts. The mantle is elongated rather than compact, and the arm spacing is uneven. Soft shading gives volume, but dense stippling weakens the requested smooth matte finish; the broad background halo makes depth less precise.

MiMo-V2.6-Pro

An appealing rabbit with balanced framing, expressive eyes and purposeful costume accents. Simple frontal construction limits anatomical and spatial accomplishment. The orange orb provides an effective luminous focal point, but unreadable wrist connections weaken the requested gestures and prevent stronger integrity credit.

Score breakdown

CategoryClaude Sonnet 5.5MiMo-V2.6-Pro
Task & likeness8.0/106.5/10
Anatomy & construction8.0/105.0/10
Space & placement8.0/105.5/10
Light & reflections7.5/106.5/10
Purposeful detail8.0/106.5/10
Artistry & character8.0/105.0/10
Materials & effects8.0/106.5/10
Visual integrity8.5/106.0/10

Benchmark task

Claude Sonnet 5.5

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

MiMo-V2.6-Pro

A small rabbit in an explorer outfit floats with a luminous orb. The scene tests character anatomy, pose and the placement of geometric forms around it.

Mona Lisa

Same task instructions

Precise visual recall and portrait reconstruction.

The judgment

Claude Sonnet 5.5

The crossed hands, dark dress, restrained smile and winding landscape clearly recall the Mona Lisa. Replication is limited by the frontal symmetry, wide eyes, elongated neck and flattened fingers. Soft facial shading provides volume, but heavy darkness and pervasive crackle obscure forms. The composition is coherent; the landscape and fabric remain visibly schematic.

MiMo-V2.6-Pro

The portrait is recognizable through its dark silhouette, slight smile and muted landscape, but replication is weak. A frontal, oversized head and symmetric torso replace the reference's turned seated pose; angular, separated hands omit its central gesture. Smooth shading maintains coherence while anatomical detail, depth and material rendering remain basic.

Score breakdown

CategoryClaude Sonnet 5.5MiMo-V2.6-Pro
Task & likeness6.5/103.5/10
Anatomy & construction5.0/103.5/10
Space & placement6.0/104.0/10
Light & reflections6.5/105.0/10
Purposeful detail6.0/103.0/10
Artistry & character6.5/104.0/10
Materials & effects6.0/104.0/10
Visual integrity6.5/106.0/10

Benchmark task

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

Beach

Same task instructions

Creativity, perspective and visual beauty.

The judgment

Claude Sonnet 5.5

A richly designed beach illustration combines radiant sunset bands, intricate palm fans and playful silhouettes within a cohesive purple, coral and turquoise palette. Carefully varied accessories reward close inspection, while overlapping foreground forms and shoreline layers organize the abundant activity. Dense palm strokes compete with focal subjects; animal anatomy, relative scales and reflected silhouettes remain simplified.

MiMo-V2.6-Pro

A readable sunset beach with clear requested subjects, appealing framing and purposeful accessories. Schematic anatomy, flattened foreground objects, repetitive water highlights and sparse directional shadows limit construction and physical depth. The kite's unresolved anchor also constrains integrity.

Score breakdown

CategoryClaude Sonnet 5.5MiMo-V2.6-Pro
Task & likeness9.0/108.5/10
Anatomy & construction8.0/105.0/10
Space & placement8.5/106.0/10
Light & reflections8.5/106.5/10
Purposeful detail9.5/106.5/10
Artistry & character9.5/105.0/10
Materials & effects8.5/106.0/10
Visual integrity8.0/106.0/10

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 Sonnet 5.5

This benchmark has not been assessed yet.

MiMo-V2.6-Pro

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

Same task instructions

Scene composition and interacting subjects.

The judgment

Claude Sonnet 5.5

The raccoon clearly rides on the dog's back while the dog grips the jet ski controls. Expressive faces, vivid colors and a sweeping wake make the scene appealing. Visible limbs connect coherently, but overlapping steering paws and an indistinct control mounting weaken construction. Flat character lighting and simplified water limit depth and material realism.

MiMo-V2.6-Pro

A coherent, cheerful cartoon with recognizable animals, readable steering contact and useful small details. The dog's orientation follows the craft more successfully than a wholly frontal pose would. Simple anatomy, weak raccoon grip and compressed seating contacts still limit physical credibility. Gradients and spray provide polish without resolving complex construction.

Score breakdown

CategoryClaude Sonnet 5.5MiMo-V2.6-Pro
Task & likeness8.5/107.0/10
Anatomy & construction7.0/105.0/10
Space & placement8.0/105.5/10
Light & reflections6.5/105.5/10
Purposeful detail8.0/106.0/10
Artistry & character7.0/104.0/10
Materials & effects7.5/105.5/10
Visual integrity8.0/104.5/10

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

Same task instructions

Subject construction and spatial relationships.

The judgment

Claude Sonnet 5.5

The pelican is immediately recognizable, with an expressive face, generous bill and appealing cycling pose. Spokes, chain, feathers and scarf provide purposeful detail. The bicycle largely holds together, though overlapping angular legs obscure the far foot’s pedal contact. Clean outlines and balanced composition succeed; flat surfaces and limited directional lighting constrain depth.

MiMo-V2.6-Pro

The distinctive bill, continuous silhouette and detailed wheels establish a readable pelican cyclist. Shaped feathers and soft shading add character, but jointless legs, crowded pedal contacts, absent steering contact and loosely directional lighting limit the construction. The comparisons support retaining the baseline category scores.

Score breakdown

CategoryClaude Sonnet 5.5MiMo-V2.6-Pro
Task & likeness9.0/106.5/10
Anatomy & construction7.5/105.0/10
Space & placement7.5/106.0/10
Light & reflections6.5/105.5/10
Purposeful detail8.0/106.0/10
Artistry & character7.5/106.0/10
Materials & effects6.5/105.5/10
Visual integrity8.0/106.0/10

Benchmark task

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