STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Kimi K3.1 Pro vs Qwen3.8-Flash

Kimi K3.1 Pro leads Qwen3.8-Flash by 10.1 points on StealthMark, 56.7 to 46.6. It leads on 5 of 9 benchmarks, including both games, and Qwen3.8-Flash on 4. 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

56.7/100Overall rank 11/53
46.6/100Overall rank 23/53

General Intelligence

53.9/100
38.5/100

Visual Intelligence

62.0/100
60.3/100

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

Open or local

Local modelOpen model · Qwen Community 1.0

BENCHMARK BY BENCHMARK

Where each model leads

  • Kimi K3.1 Pro
  • Qwen3.8-Flash
  • Other models
  • Median

DATASHEET

Specs and pricing

Kimi K3.1 Pro scores higher on StealthMark and runs 1.6× faster in our speed test. Qwen3.8-Flash is 26× cheaper per output token. Both take about 1M tokens of context.

  • Kimi K3.1 Pro
  • Qwen3.8-Flash
  • Other models
  • Median
PricePer 1M output tokens, input below
Kimi K3.1 Pro: $10$2 inputQwen3.8-Flash: $0.3826× cheaper$0.11 input
Context windowTokens per request, max output below
Kimi K3.1 Pro: 1MTied1M max outputQwen3.8-Flash: 1MTied128K max output
Output speedTokens per second, our measurement
Kimi K3.1 Pro: 1171.6× fastertokens/sQwen3.8-Flash: 75tokens/s
SizeTotal and active parameters
Kimi K3.1 Pro: 2.8T104B activeEstimatedQwen3.8-Flash: 180B6B activeEstimated
Developer
Moonshot AIQwen / Alibaba Cloud
Released
23 Oct 202626 Aug 2026
Origin
ChinaBoth
Input → output
Text, image, video → textBoth
Architecture
Post-trained version of Kimi K3, a Mixture-of-Experts modelHosted Flash based on Flash-Next: sparse attention and n-gram memory; Flash-Next previews Qwen 4 architecture

Full datasheets, every price and sourceKimi K3.1 Pro ↗Qwen3.8-Flash ↗

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.

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

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

Qwen3.8-Flash 29.7/100Rank 33/47

Survived 1 of 3
Foresight: complete playing field
Level 35 ptsTurn 10 / 20

Points per level

LevelKimi K3.1 ProQwen3.8-Flash
Level 1Second Thoughts
15 ptsOut of lives
26 ptsSurvived
Level 2Pressure Pot
12 ptsOut of lives
3 ptsOut of lives
Level 3Hide or Flight
15 ptsSurvived
5 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.

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

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

Qwen3.8-Flash 69.8/100Rank 16/48

Cleared 5 of 5
Latch: complete playing field
Level 520 ptsTurn 30 / 40

Points per level

LevelKimi K3.1 ProQwen3.8-Flash
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.8 ptsCleared
Level 3Relay vault
19.2 ptsCleared
18.8 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
17.2 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
19.8 ptsCleared
20 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

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.

Qwen3.8-Flash

The full-frame illustration supports a central steel sphere, an airborne black blob and the relative ordering of cyan and crimson. Its faint floor return and symmetric repetitions provide sparse mirror structure; outer chains, large reflected images, nested imagery and emitter mapping remain deficient. Vertical framing is substantially displaced, and paint contact histories remain unresolved.

Score breakdown

CategoryKimi K3.1 ProQwen3.8-Flash
State at 600 ms23.5/2519.0/25
Camera and placement10.5/153.5/15
Reflections26.0/1209.5/120
Materials and scale7.0/104.0/10
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

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.

Qwen3.8-Flash

A coherent, appealing fantasy illustration with disciplined framing, luminous teal accents and consistent ornament. Most requested elements are clearly present. The bear-like facial proportions, lowered resting hand, obscured bent-leg construction and limited fabric modeling constrain likeness and anatomical clarity; glow effects are attractive but weakly integrated with surrounding surfaces.

Score breakdown

CategoryKimi K3.1 ProQwen3.8-Flash
Task & likeness8.0/108.0/10
Anatomy & construction5.5/107.0/10
Space & placement6.5/108.0/10
Light & reflections6.5/107.5/10
Purposeful detail7.5/108.0/10
Artistry & character7.0/107.5/10
Materials & effects7.0/107.5/10
Visual integrity7.0/108.5/10

Benchmark task

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.

Qwen3.8-Flash

A floating capybara in ornate robes tests character anatomy, layered fabric and the placement of surrounding luminous forms.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

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.

Qwen3.8-Flash

The dark dress, crossed hands and hazy landscape evoke the Mona Lisa, but replication is limited by a generic frontal face, coarse smile and poorly articulated fingers. The gold frame has clearer definition than the portrait. Heavy mottling obscures features, while soft shading provides some volume without convincing anatomical detail.

Score breakdown

CategoryKimi K3.1 ProQwen3.8-Flash
Task & likeness5.0/105.0/10
Anatomy & construction5.0/104.5/10
Space & placement5.5/105.5/10
Light & reflections6.0/105.5/10
Purposeful detail5.5/105.5/10
Artistry & character6.0/105.5/10
Materials & effects5.0/105.5/10
Visual integrity6.5/105.5/10

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

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.

Qwen3.8-Flash

Sweeping palms, coordinated sunset colors and a central reflection create an expressive beach composition with clear depth. Birds, animals and varied activities thoroughly realize the brief. Small figures and animal anatomy remain rudimentary, water movement is schematic, and contact shadows are weak. Scattered foreground details and the clipped orange disk limit the finish.

Score breakdown

CategoryKimi K3.1 ProQwen3.8-Flash
Task & likeness8.5/109.0/10
Anatomy & construction5.5/107.0/10
Space & placement5.5/108.0/10
Light & reflections6.5/107.5/10
Purposeful detail6.5/108.5/10
Artistry & character5.5/108.0/10
Materials & effects6.5/106.5/10
Visual integrity7.5/107.0/10

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

Kimi K3.1 Pro

This benchmark has not been assessed yet.

Qwen3.8-Flash

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

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.

Qwen3.8-Flash

The raccoon clearly rides the dog's back, with expressive features and appealing blue-orange color contrast. The dog's paws do not clearly operate connected controls, and the shallow vehicle lacks convincing jet ski construction. Clean outlines support the cartoon style, but generic shading and blurred water streaks limit depth and motion.

Score breakdown

CategoryKimi K3.1 ProQwen3.8-Flash
Task & likeness7.0/107.0/10
Anatomy & construction5.5/105.5/10
Space & placement6.0/106.5/10
Light & reflections5.5/105.5/10
Purposeful detail7.0/107.0/10
Artistry & character6.0/106.5/10
Materials & effects6.0/105.5/10
Visual integrity7.0/107.0/10

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

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.

Qwen3.8-Flash

The pelican's expressive face, oversized bill and flowing scarf create an appealing focal point. The bicycle has recognizable frame, chain and wheel construction, but the far foot lacks a clear pedal connection and the wing's steering contact is ambiguous. Clean contours and gentle gradients support the illustration; simplified volume and weak directional shadows limit depth.

Score breakdown

CategoryKimi K3.1 ProQwen3.8-Flash
Task & likeness8.5/108.5/10
Anatomy & construction7.5/108.0/10
Space & placement6.5/107.5/10
Light & reflections6.5/106.5/10
Purposeful detail7.5/108.0/10
Artistry & character7.5/108.0/10
Materials & effects6.5/107.0/10
Visual integrity7.5/107.5/10

Benchmark task

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