STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Sol vs Kimi K3.1 Pro

GPT-6.1 Sol leads Kimi K3.1 Pro by 11.1 points on StealthMark, 67.8 to 56.7. 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
56.7/100Overall rank 11/53

General Intelligence

64.4/100
53.9/100

Visual Intelligence

74.1/100
62.0/100

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

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6.1 Sol
  • Kimi K3.1 Pro
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-6.1 Sol scores higher on StealthMark. Kimi K3.1 Pro runs 2.3× faster in our speed test. Both take about 1.05M tokens of context.

  • GPT-6.1 Sol
  • Kimi K3.1 Pro
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Sol: $10Tied$2 inputKimi K3.1 Pro: $10Tied$2 input
Context windowTokens per request, max output below
GPT-6.1 Sol: 1.05MTied128K max outputKimi K3.1 Pro: 1MTied1M max output
Output speedTokens per second, our measurement
GPT-6.1 Sol: 51tokens/sKimi K3.1 Pro: 1172.3× fastertokens/s
SizeTotal and active parameters
GPT-6.1 Sol: Not disclosedKimi K3.1 Pro: 2.8T104B activeEstimated
Developer
OpenAIMoonshot AI
Released
29 Sep 202623 Oct 2026
Origin
United StatesChina
Input → output
Text, image → textText, image, video → text
Architecture
Not publishedPost-trained version of Kimi K3, a Mixture-of-Experts model

Full datasheets, every price and sourceGPT-6.1 Sol ↗Kimi K3.1 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

Kimi K3.1 Pro 61.1/100Rank 10/47

Survived 1 of 3
Foresight: complete playing field
Level 315 ptsTurn 20 / 20

Points per level

LevelGPT-6.1 SolKimi K3.1 Pro
Level 1Second Thoughts
26 ptsSurvived
15 ptsOut of lives
Level 2Pressure Pot
6 ptsOut of lives
12 ptsOut of lives
Level 3Hide or Flight
18 ptsSurvived
15 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

Kimi K3.1 Pro 81.8/100Rank 8/48

Cleared 5 of 5
Latch: complete playing field
Level 519.8 ptsTurn 31 / 40

Points per level

LevelGPT-6.1 SolKimi K3.1 Pro
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10.2 ptsClearedFinished early · 1 beacon left
9.8 ptsCleared
Level 3Relay vault
19.2 ptsCleared
19.2 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
18.2 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
20.6 ptsCleared
19.8 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.

Kimi K3.1 Pro

The settled sphere, separate airborne black paint and crimson-before-cyan interaction are supported, with a modest crimson travel overshoot. A shared downward framing displacement remains after accounting for the square canvas. The principal limitation is the reflection system: sparse sphere copies and generic curved bands omit most of the ordered mirror-room structure. Materials receive a small upward revision because bounded bright images and dark bands visibly establish some polish, while soft shading and bulky paint remain separate weaknesses.

Score breakdown

CategoryGPT-6.1 SolKimi K3.1 Pro
State at 600 ms24.0/2523.5/25
Camera and placement15.0/1510.5/15
Reflections35.0/12026.0/120
Materials and scale10.0/107.0/10
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

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.

Kimi K3.1 Pro

The transformed reflection, attentive pose and constellation anatomy clearly communicate introspection. Purposeful fine details enrich a coherent composition. Tubular limbs, crowded lower-body overlaps, shallow depth and limited cast lighting keep the overall execution within the competent range.

Score breakdown

CategoryGPT-6.1 SolKimi K3.1 Pro
Task & likeness8.5/108.0/10
Anatomy & construction7.5/105.5/10
Space & placement8.0/106.5/10
Light & reflections7.0/106.5/10
Purposeful detail7.5/107.5/10
Artistry & character7.5/107.0/10
Materials & effects7.0/107.0/10
Visual integrity8.0/107.0/10

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.

Kimi K3.1 Pro

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

Same 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.

Kimi K3.1 Pro

A coherent, recognizable interpretation with controlled color and readable landscape layers. Replication is limited by the frontal seated construction, elongated facial proportions and oversized, weakly articulated hands. Smooth shading supplies some volume but little of the reference's subtle expression, fabric structure or atmospheric transitions.

Score breakdown

CategoryGPT-6.1 SolKimi K3.1 Pro
Task & likeness6.5/105.0/10
Anatomy & construction5.5/105.0/10
Space & placement6.5/105.5/10
Light & reflections6.5/106.0/10
Purposeful detail5.5/105.5/10
Artistry & character6.5/106.0/10
Materials & effects6.0/105.0/10
Visual integrity7.0/106.5/10

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.

Kimi K3.1 Pro

A coherent, playful beach illustration with readable animals, an organized composition and an aligned sunset reflection. Connected silhouettes, sand texture and atmospheric effects demonstrate controlled execution. Simplified joints, flattened foreground viewpoints and inconsistent shadows limit anatomical and spatial credibility.

Score breakdown

CategoryGPT-6.1 SolKimi K3.1 Pro
Task & likeness8.5/108.5/10
Anatomy & construction7.5/105.5/10
Space & placement7.5/105.5/10
Light & reflections7.5/106.5/10
Purposeful detail7.5/106.5/10
Artistry & character7.0/105.5/10
Materials & effects7.0/106.5/10
Visual integrity8.5/107.5/10

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.

Kimi K3.1 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.

Kimi K3.1 Pro

The additional comparisons support retaining the assessment. Readable steering, shaped animal contours and purposeful details coexist with simplified joints, a frontal passenger whose seated weight is weakly conveyed, and limited physical lighting. The angled craft establishes more depth than the riding pose resolves.

Score breakdown

CategoryGPT-6.1 SolKimi K3.1 Pro
Task & likeness8.5/107.0/10
Anatomy & construction7.5/105.5/10
Space & placement7.5/106.0/10
Light & reflections6.5/105.5/10
Purposeful detail8.0/107.0/10
Artistry & character8.0/106.0/10
Materials & effects7.5/106.0/10
Visual integrity8.5/107.0/10

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

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.

Kimi K3.1 Pro

A characterful coastal illustration with controlled contours and varied feather, accessory and bicycle detail. Layered scenery and subtle shading enrich the presentation. Soft leg articulation, unresolved riding contacts, shallow depth and generalized lighting limit physical precision.

Score breakdown

CategoryGPT-6.1 SolKimi K3.1 Pro
Task & likeness9.0/108.5/10
Anatomy & construction7.0/107.5/10
Space & placement8.0/106.5/10
Light & reflections7.0/106.5/10
Purposeful detail8.0/107.5/10
Artistry & character8.5/107.5/10
Materials & effects7.5/106.5/10
Visual integrity8.0/107.5/10

Benchmark task

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