STEALTHMARK · HEAD TO HEAD

All comparisons ↗

DeepSeek-V4.1-Flash vs Step 5 Preview

DeepSeek-V4.1-Flash leads Step 5 Preview by 11.0 points on StealthMark, 50.0 to 39.0. It leads on 8 of 9 benchmarks, including both games, and Step 5 Preview on 1. DeepSeek-V4.1-Flash scores higher on Beach, with its largest category advantage in prompt & likeness.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

50.0/100Overall rank 16/53
39.0/100Overall rank 36/53

General Intelligence

48.5/100
37.1/100

Visual Intelligence

53.0/100
41.9/100

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

Open modelMIT

BENCHMARK BY BENCHMARK

Where each model leads

  • DeepSeek-V4.1-Flash
  • Step 5 Preview
  • Other models
  • Median

DATASHEET

Specs and pricing

Both take about 1M tokens of context.

  • DeepSeek-V4.1-Flash
  • Step 5 Preview
  • Other models
  • Median
PricePer 1M output tokens, input below
DeepSeek-V4.1-Flash: $1.13$0.28 inputStep 5 Preview: No list price
Context windowTokens per request, max output below
DeepSeek-V4.1-Flash: 1MTied384K max outputStep 5 Preview: 1MTied
Output speedTokens per second, our measurement
DeepSeek-V4.1-Flash: 242tokens/sStep 5 Preview: Not measured
SizeTotal and active parameters
DeepSeek-V4.1-Flash: 763B16B activeStep 5 Preview: 600B27B active
Developer
DeepSeek-AIStepFun
Released
10 Sep 2026Not published
Origin
ChinaNot published
Input → output
Text, image → textText, image, video → text
Architecture
20-layer encoder + 20-layer decoder with CSA2, Single-Pass mHC, Engram n-gram memory and DSpark/MTPSparse mixture-of-experts; 92 layers (88 MoE), 352 routed experts with 8 selected per token plus a shared expert; grouped-query attention with 512-token sliding windows and full attention every fourth layer; 3 multi-token-prediction layers; vision tower for image and video input

Full datasheets, every price and sourceDeepSeek-V4.1-Flash ↗Step 5 Preview ↗

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.

DeepSeek-V4.1-Flash 55.4/100Rank 12/49

Survived 1 of 3
Foresight: complete playing field
Level 318 ptsTurn 20 / 20

Step 5 Preview 59.9/100Rank 42/491 of 3 levels

1 of 3 played
Foresight: complete playing field
Level 122 ptsTurn 28 / 28

Points per level

LevelDeepSeek-V4.1-FlashStep 5 Preview
Level 1Second Thoughts
16 ptsOut of lives
22 ptsSurvived
Level 2Pressure Pot
7 ptsOut of lives
Pending
Level 3Hide or Flight
18 ptsSurvived
Pending

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.

DeepSeek-V4.1-Flash 65.2/100Rank 21/50

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

Step 5 Preview 40.7/100Rank 28/50

Cleared 4 of 5
Latch: complete playing field
Level 515 ptsTurn 35 / 40

Points per level

LevelDeepSeek-V4.1-FlashStep 5 Preview
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9 ptsCleared
9 ptsCleared
Level 3Relay vault
17.2 ptsClearedFinished early · 3 beacons left
18.6 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
15.6 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
20.6 ptsCleared
15 ptsFinished early

Newton's Mirror

Same task instructions

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

The judgment

DeepSeek-V4.1-Flash

The first wall and floor images provide limited reflection geometry, but the room's mirror recurrence is substantially incomplete, particularly the outer-edge chains and lateral sightlines. The main sphere and its large reflected images lack ordered, curved room and virtual-sphere imagery. Repeated emitter mapping is missing from both planar mirrors and spherical surfaces.

Step 5 Preview

The main sphere, airborne black and small colored features occupy broadly appropriate positions. Most of the defining mirror system is absent, and paint interaction remains only partially supported. The small paint features do not visibly establish a separate volume-scale violation.

Score breakdown

CategoryDeepSeek-V4.1-FlashStep 5 Preview
State at 600 ms23.5/2520.0/25
Camera and placement13.5/1513.5/15
Reflections30.0/12020.0/120
Materials and scale8.0/107.0/10
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

DeepSeek-V4.1-Flash

Expressive faces, cobalt coloring and a flowing diagonal composition make the mutual inspection charming. Execution is uneven: the long pointed flipper lacks a convincing grip, the enlarged shrimp face appears detached from its body, and the large lens is oval. Flat anatomical shading and an unexplained purple ringed patch beneath the whale weaken the requested polished depth.

Step 5 Preview

A charming diagonal climber and warm palette communicate the central idea. Simple rounded construction, crowded limb counting, uncertain footholds and an unattached upper shelf limit its physical coherence. Growth bands and the yarn trail add specificity, but the requested material distinctions and unravelled bootie remain underdeveloped.

Score breakdown

CategoryDeepSeek-V4.1-FlashStep 5 Preview
Task & likeness7.0/106.0/10
Anatomy & construction6.5/104.5/10
Space & placement6.5/105.0/10
Light & reflections6.0/105.5/10
Purposeful detail7.0/105.5/10
Artistry & character7.5/105.0/10
Materials & effects7.0/106.0/10
Visual integrity7.0/105.0/10

Benchmark task

DeepSeek-V4.1-Flash

A whale and a tiny shrimp examine one another through bubble lenses, with an octopus nearby. The scene tests interacting characters, differences in scale and transparent materials.

Step 5 Preview

Character scenes test expression, anatomy, materials and coherent visual construction.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

DeepSeek-V4.1-Flash

The centered portrait, dark hair, crossed hands and muted landscape make the reference recognizable. Replication is limited by the frontal pose, staring eyes and weakly defined smile. Hands are overlapping oval masses with almost no finger articulation, while wrists disappear into sleeves. Soft gradients suggest volume, but broad, indistinct surfaces and faint stray lines leave the drawing basic and uneven.

Step 5 Preview

A recognizable, coherent simplification with purposeful facial contours and differentiated fingers. These provide more construction and detail than the broad silhouette alone suggests. The oversized face, frontal seated pose, unresolved wrists and sparse landscape still substantially limit likeness, depth and finish.

Score breakdown

CategoryDeepSeek-V4.1-FlashStep 5 Preview
Task & likeness3.5/104.0/10
Anatomy & construction3.0/104.0/10
Space & placement4.5/104.0/10
Light & reflections4.5/103.5/10
Purposeful detail3.0/104.0/10
Artistry & character4.0/104.0/10
Materials & effects3.0/103.0/10
Visual integrity5.5/103.5/10

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

DeepSeek-V4.1-Flash

The glowing sunset, silhouetted palm and playful foreground create a coherent, appealing beach illustration. Birds, crab, boat and reflections fulfill the brief. The airborne animals have weakly defined anatomy and little convincing splash interaction. Broad, blurred reflections and largely flat surfaces limit depth and finish.

Step 5 Preview

A recognizable sunset beach with clear warm-cool contrast and playful accessories. Basic animal construction, shallow foreground placement and schematic reflections limit spatial and physical credibility. Sparse descriptive detail and abruptly ended sky bands constrain the finish.

Score breakdown

CategoryDeepSeek-V4.1-FlashStep 5 Preview
Task & likeness8.0/104.0/10
Anatomy & construction5.5/103.0/10
Space & placement6.5/103.5/10
Light & reflections6.5/103.5/10
Purposeful detail5.5/103.0/10
Artistry & character5.0/103.0/10
Materials & effects6.0/103.5/10
Visual integrity5.5/104.0/10

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

DeepSeek-V4.1-Flash

This benchmark has not been assessed yet.

Step 5 Preview

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

Different task instructions

Scene composition and interacting subjects.

The judgment

DeepSeek-V4.1-Flash

The sunset palette and silhouetted grouping establish an appealing scene. A masked rider sits above a pointed-eared dog, but merged body shapes leave limbs and support unresolved. The boatlike craft lacks readable steering controls, so the requested action is unclear. Sparse facial marks and glowing spray dots offer limited detail.

Step 5 Preview

Recognizable animals, a bright palette and identifying accessories support a basic cartoon. Primitive anatomy, partial seated support, unresolved steering and weak hull-water contact limit the central action. Lighting and spray provide atmosphere without establishing convincing physical depth.

Score breakdown

CategoryDeepSeek-V4.1-FlashStep 5 Preview
Task & likeness5.0/104.0/10
Anatomy & construction4.0/104.5/10
Space & placement5.5/103.0/10
Light & reflections6.0/103.5/10
Purposeful detail3.5/104.0/10
Artistry & character4.0/103.5/10
Materials & effects5.0/103.0/10
Visual integrity6.0/103.0/10

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

DeepSeek-V4.1-Flash

A recognizable pelican rides a brightly colored bicycle against a striking sunset. The sweeping bill, trailing scarf and circular wheels create a controlled composition. Both legs connect, but pedal linkage, body support and the wing's handlebar grip remain loosely resolved. Clean vector shapes and feather details work well; simplified shading limits volume and integration with the sunset light.

Step 5 Preview

The pelican and bicycle are recognizable, with a pleasant palette and basic diffuse shading. The riding relationship fails physically: the bird is unsupported, the front wheel is unmounted, and pedalling is unresolved. Simple geometric construction and sparse material treatment further limit the drawing.

Score breakdown

CategoryDeepSeek-V4.1-FlashStep 5 Preview
Task & likeness8.5/103.0/10
Anatomy & construction7.0/103.0/10
Space & placement7.5/103.0/10
Light & reflections7.0/103.0/10
Purposeful detail6.5/104.0/10
Artistry & character8.0/103.0/10
Materials & effects7.0/103.0/10
Visual integrity8.0/102.0/10

Benchmark task

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