STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6 Luna vs Kimi K3.1 Pro

Kimi K3.1 Pro leads GPT-6 Luna by 17.6 points on StealthMark, 56.7 to 39.1. It leads on 8 of 9 benchmarks, including both games, and GPT-6 Luna on 1. Kimi K3.1 Pro scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

39.1/100Overall rank 35/53
56.7/100Overall rank 11/53

General Intelligence

31.3/100
53.9/100

Visual Intelligence

52.0/100
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

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6 Luna
  • Kimi K3.1 Pro
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-6 Luna is 20× cheaper per output token and runs 12% faster in our speed test. Kimi K3.1 Pro scores higher on StealthMark. Both take about 1.05M tokens of context.

  • GPT-6 Luna
  • Kimi K3.1 Pro
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6 Luna: $0.5020× cheaper$0.10 inputKimi K3.1 Pro: $10$2 input
Context windowTokens per request, max output below
GPT-6 Luna: 1.05MTied128K max outputKimi K3.1 Pro: 1MTied1M max output
Output speedTokens per second, our measurement
GPT-6 Luna: 13112% fastertokens/sKimi K3.1 Pro: 117tokens/s
SizeTotal and active parameters
GPT-6 Luna: Not disclosedKimi K3.1 Pro: 2.8T104B activeEstimated
Developer
OpenAIMoonshot AI
Released
22 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 Luna ↗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 Luna 29.8/100Rank 32/47

Survived 0 of 3
Foresight: complete playing field
Level 36 ptsTurn 7 / 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 LunaKimi K3.1 Pro
Level 1Second Thoughts
15 ptsOut of lives
15 ptsOut of lives
Level 2Pressure Pot
5 ptsOut of lives
12 ptsOut of lives
Level 3Hide or Flight
6 ptsOut of lives
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 Luna 44.0/100Rank 25/48

Cleared 4 of 5
Latch: complete playing field
Level 513 ptsTurn 15 / 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 LunaKimi K3.1 Pro
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
8.8 ptsClearedFinished early · 1 beacon left
9.8 ptsCleared
Level 3Relay vault
17 ptsCleared1 beacon left
19.2 ptsCleared
Level 4Passing bay
15.8 ptsClearedFinished early · 3 beacons left
18.2 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
13 ptsFinished early
19.8 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

GPT-6 Luna

The schematic scene supports the paint contact order and compact paint scale. Its low, undersized main sphere and incorrectly placed wall images depart from the reference geometry. A few shrinking wall images provide limited optical organization, while absent lateral recursion and outer chains, broad sphere ribbons and isolated panel highlights leave most nested room and emitter mapping undeveloped.

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 LunaKimi K3.1 Pro
State at 600 ms22.0/2523.5/25
Camera and placement3.5/1510.5/15
Reflections5.0/12026.0/120
Materials and scale7.0/107.0/10
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 Luna

Sixfold symmetry, pale coloring and six outward-facing heads establish the motif. However, every neck floats clear of the knot. Squared outer sections replace the required semicircular lobes, and the large stepped opening lacks a regular hexagonal contour. Repeated scales and soft shading suggest skin, but translucent crossings and doubled edges weaken the living, interwoven construction.

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 LunaKimi K3.1 Pro
Task & likeness4.5/108.0/10
Anatomy & construction3.5/105.5/10
Space & placement5.5/106.5/10
Light & reflections5.0/106.5/10
Purposeful detail5.0/107.5/10
Artistry & character5.0/107.0/10
Materials & effects5.0/107.0/10
Visual integrity4.5/107.0/10

Benchmark task

GPT-6 Luna

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 Luna

The dark veil, crossed arms, restrained smile and layered landscape clearly evoke Mona Lisa. Clean contours and muted colors create a coherent illustration. Replication is limited by enlarged, outlined eyes, simplified facial volume, broad shoulders and indistinct overlapping hands. Gradients suggest depth, but lack the original's subtle painterly transitions.

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 LunaKimi K3.1 Pro
Task & likeness4.5/105.0/10
Anatomy & construction4.0/105.0/10
Space & placement5.5/105.5/10
Light & reflections5.0/106.0/10
Purposeful detail5.0/105.5/10
Artistry & character4.5/106.0/10
Materials & effects5.0/105.0/10
Visual integrity6.0/106.5/10

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 Luna

The warm sky, layered sea and framing palms create an appealing beach composition. Animals, birds, toys and reflected sunlight fulfill the brief. Human anatomy remains schematic, and simplified figures offer limited expression. Missing shadows and the dolphin's splashless jump weaken physical grounding, while clean silhouettes and readable small details support the illustration.

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 LunaKimi K3.1 Pro
Task & likeness7.5/108.5/10
Anatomy & construction5.0/105.5/10
Space & placement7.5/105.5/10
Light & reflections5.0/106.5/10
Purposeful detail7.0/106.5/10
Artistry & character5.0/105.5/10
Materials & effects6.5/106.5/10
Visual integrity6.0/107.5/10

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 Luna

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 Luna

Expressive faces, warm sunset colors and clean silhouettes create an appealing illustration. The raccoon sits on the dog's back, but the dog's grip and steering linkage remain unclear. The broad hull resembles a speedboat, and flat shading, absent sun reflections and modest water displacement limit depth and motion.

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 LunaKimi K3.1 Pro
Task & likeness8.0/107.0/10
Anatomy & construction5.5/105.5/10
Space & placement7.5/106.0/10
Light & reflections6.0/105.5/10
Purposeful detail7.0/107.0/10
Artistry & character5.5/106.0/10
Materials & effects6.5/106.0/10
Visual integrity5.0/107.0/10

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 Luna

The pelican’s distinctive bill and the coordinated vintage poster palette make an appealing illustration. Circular wheels, orderly spokes and clean lettering strengthen the design. Riding mechanics are less convincing: neither wing reaches the handlebars, pedal contact is ambiguous, and the drivetrain is incomplete. The wheels sit against water without a clear supporting surface. Flat lighting limits volume.

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 LunaKimi K3.1 Pro
Task & likeness8.0/108.5/10
Anatomy & construction5.0/107.5/10
Space & placement6.5/106.5/10
Light & reflections6.5/106.5/10
Purposeful detail7.5/107.5/10
Artistry & character6.5/107.5/10
Materials & effects6.5/106.5/10
Visual integrity7.0/107.5/10

Benchmark task

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