STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Sol vs MiMo-V2.6-Pro

GPT-6.1 Sol leads MiMo-V2.6-Pro by 19.9 points on StealthMark, 67.8 to 47.9. It leads on all 9 benchmarks. GPT-6.1 Sol scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

67.8/100Overall rank 4/53
47.9/100Overall rank 21/53

General Intelligence

64.4/100
44.3/100

Visual Intelligence

74.1/100
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

  • GPT-6.1 Sol

Open or local

Open modelMIT

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6.1 Sol
  • MiMo-V2.6-Pro
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-6.1 Sol scores higher on StealthMark. MiMo-V2.6-Pro is 11× cheaper per output token and runs 2.3× faster in our speed test. Both take about 1.05M tokens of context.

  • GPT-6.1 Sol
  • MiMo-V2.6-Pro
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Sol: $10$2 inputMiMo-V2.6-Pro: $0.8711× cheaper$0.43 input
Context windowTokens per request, max output below
GPT-6.1 Sol: 1.05MTied128K max outputMiMo-V2.6-Pro: 1MTied128K max output
Output speedTokens per second, our measurement
GPT-6.1 Sol: 51tokens/sMiMo-V2.6-Pro: 1162.3× fastertokens/s
SizeTotal and active parameters
GPT-6.1 Sol: Not disclosedMiMo-V2.6-Pro: 1.02T42B active
Developer
OpenAIXiaomi
Released
29 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 sourceGPT-6.1 Sol ↗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.

GPT-6.1 Sol 62.0/100Rank 9/47

Survived 2 of 3
Foresight: complete playing field
Level 318 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

LevelGPT-6.1 SolMiMo-V2.6-Pro
Level 1Second Thoughts
26 ptsSurvived
4 ptsOut of lives
Level 2Pressure Pot
6 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
18 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.

GPT-6.1 Sol 87.6/100Rank 1/48

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

LevelGPT-6.1 SolMiMo-V2.6-Pro
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10.2 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

GPT-6.1 Sol

Recognizable first sphere images and several central planar lights provide limited geometric agreement. Missing outer chains, truncated panel sequences and simplified interiors across the main, side and floor spheres leave most of the recursive reflection structure unsupported.

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

CategoryGPT-6.1 SolMiMo-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

GPT-6.1 Sol

Six outward-facing heads and evenly arranged loops make the pale interlocking knot immediately readable. Uniform widths, angular inner bends and fine scales preserve its ornamental geometry. The bodies feel more like textured tubes than living muscle: shading is subdued, crossing contact shadows are weak, and visible curved seams interrupt surface continuity. Small heads have readable eyes and jaws but limited anatomical depth.

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

CategoryGPT-6.1 SolMiMo-V2.6-Pro
Task & likeness8.5/106.5/10
Anatomy & construction7.5/105.0/10
Space & placement8.0/105.5/10
Light & reflections7.0/106.5/10
Purposeful detail7.5/106.5/10
Artistry & character7.5/105.0/10
Materials & effects7.0/106.5/10
Visual integrity8.0/106.0/10

Benchmark task

GPT-6.1 Sol

A pale serpent woven into an interlocking knot tests connected anatomy, repeated structure and readable overlaps. Organic surface detail must work with the overall geometry.

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

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

GPT-6.1 Sol

The recognizable pose, dark clothing and misty landscape form a coherent portrait. Soft facial shading creates volume, but the broad face, outlined eyes and simplified smile limit likeness. Overlapping hands have flattened fingers and ambiguous separation. Angular landscape shapes and sparse fabric detail keep the execution competent rather than masterful.

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

CategoryGPT-6.1 SolMiMo-V2.6-Pro
Task & likeness6.5/103.5/10
Anatomy & construction5.5/103.5/10
Space & placement6.5/104.0/10
Light & reflections6.5/105.0/10
Purposeful detail5.5/103.0/10
Artistry & character6.5/104.0/10
Materials & effects6.0/104.0/10
Visual integrity7.0/106.0/10

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

GPT-6.1 Sol

A cohesive sunset palette, sweeping shoreline and framing palm create an appealing beach illustration. Animals, birds, play and a prominent sun reflection fulfill the brief. Connected but schematic figures and simplified dolphin anatomy limit construction; stepped reflections and mostly flat surfaces limit lighting and material depth. Small beach accessories remain readable and edges are clean.

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

CategoryGPT-6.1 SolMiMo-V2.6-Pro
Task & likeness8.5/108.5/10
Anatomy & construction7.5/105.0/10
Space & placement7.5/106.0/10
Light & reflections7.5/106.5/10
Purposeful detail7.5/106.5/10
Artistry & character7.0/105.0/10
Materials & effects7.0/106.0/10
Visual integrity8.5/106.0/10

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

GPT-6.1 Sol

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

GPT-6.1 Sol

The masked raccoon rides the dog's back, and the dog's forepaw meets a handlebar connected to the deck. Expressive faces, a striped tail and sweeping wake create an appealing composition. Overlapping bodies compress the seating and rear-leg anatomy; hull depth and sunset illumination remain schematic.

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

CategoryGPT-6.1 SolMiMo-V2.6-Pro
Task & likeness8.5/107.0/10
Anatomy & construction7.5/105.0/10
Space & placement7.5/105.5/10
Light & reflections6.5/105.5/10
Purposeful detail8.0/106.0/10
Artistry & character8.0/104.0/10
Materials & effects7.5/105.5/10
Visual integrity8.5/104.5/10

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

GPT-6.1 Sol

A clearly recognizable pelican rides a well-composed bicycle through a warm coastal scene. The expressive bill, restrained palette and carefully drawn wheels give the illustration character. Leg-to-pedal connections are less convincing, especially the obscured far foot. Lighting provides gentle volume but little directional shadow. The small subtitle is clipped at the lower border.

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

CategoryGPT-6.1 SolMiMo-V2.6-Pro
Task & likeness9.0/106.5/10
Anatomy & construction7.0/105.0/10
Space & placement8.0/106.0/10
Light & reflections7.0/105.5/10
Purposeful detail8.0/106.0/10
Artistry & character8.5/106.0/10
Materials & effects7.5/105.5/10
Visual integrity8.0/106.0/10

Benchmark task

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