STEALTHMARK · HEAD TO HEAD

All comparisons ↗

DeepSeek-V4.1-Flash-1017 vs GPT-5.5

DeepSeek-V4.1-Flash-1017 leads GPT-5.5 by 27.9 points on StealthMark, 59.2 to 31.3. It leads on all 7 benchmarks with results for both. DeepSeek-V4.1-Flash-1017 scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

59.2/100Overall rank 9/53
31.3/100Overall rank 43/53

General Intelligence

56.8/100
26.8/100

Visual Intelligence

63.5/100
36.3/100

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-5.5Multi-step reasoning not measured

Open or local

Open modelMIT

BENCHMARK BY BENCHMARK

Where each model leads

  • DeepSeek-V4.1-Flash-1017
  • GPT-5.5
  • Other models
  • Median

DATASHEET

Specs and pricing

DeepSeek-V4.1-Flash-1017 scores higher on StealthMark, is 25× cheaper per output token and runs 1.6× faster in our speed test. Both take about 1M tokens of context.

  • DeepSeek-V4.1-Flash-1017
  • GPT-5.5
  • Other models
  • Median
PricePer 1M output tokens, input below
DeepSeek-V4.1-Flash-1017: $1.2025× cheaper$0.30 inputGPT-5.5: $30$5 input
Context windowTokens per request, max output below
DeepSeek-V4.1-Flash-1017: 1MTied384K max outputGPT-5.5: 1.05MTied128K max output
Output speedTokens per second, our measurement
DeepSeek-V4.1-Flash-1017: 3101.6× fastertokens/sGPT-5.5: 193tokens/s
SizeTotal and active parameters
DeepSeek-V4.1-Flash-1017: 763B16B activeEstimatedGPT-5.5: Not disclosed
Developer
DeepSeek-AIOpenAI
Released
17 Oct 202623 Apr 2026
Origin
ChinaUnited States
Input → output
Text, image → textBoth
Architecture
Sparse mixture-of-experts with a causal encoder-decoder design and native image understanding.Not published

Full datasheets, every price and sourceDeepSeek-V4.1-Flash-1017 ↗GPT-5.5 ↗

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-1017 52.9/100Rank 15/47

Survived 1 of 3
Foresight: complete playing field
Level 310 ptsTurn 15 / 20

Points per level

LevelDeepSeek-V4.1-Flash-1017GPT-5.5
Level 1Second Thoughts
26 ptsSurvived
No run
Level 2Pressure Pot
7 ptsOut of lives
No run
Level 3Hide or Flight
10 ptsOut of lives
No run

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-1017 73.9/100Rank 13/48

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

Points per level

LevelDeepSeek-V4.1-Flash-1017GPT-5.5
Level 1Hold the door
5.2 ptsCleared
No run
Level 2Crossfeed
9.8 ptsCleared
No run
Level 3Relay vault
19.2 ptsCleared
No run
Level 4Passing bay
16.4 ptsClearedFinished early · 3 beacons left
No run
Level 5Second thoughts
20 ptsCleared
No run

Newton's Mirror

Same task instructions

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

The judgment

DeepSeek-V4.1-Flash-1017

Principal sphere and airborne-black placements are supported, and diminishing bilateral chains provide limited optical structure. Missing nested imagery, incomplete outer chains, distorted first images and sparse emitter recurrence remain the dominant weaknesses. Oversized paint bodies and unresolved cyan contact impose separate limitations.

GPT-5.5

The paint ordering and separate black bead support part of the physical state, but adhesion and rotational transport remain only partly established. The sweeping cyan arc and long crimson lobes do not clearly communicate the limited time since their respective impacts. The main sphere is too large and too low, and the black bead is below its required projected position. Displaced isolated sphere images, a flattened floor echo and missing recursive, nested and emitter reflections provide little coherent optical structure. The colored paint is excessively bulky for the specified quantities.

Score breakdown

CategoryDeepSeek-V4.1-Flash-1017GPT-5.5
State at 600 ms23.0/2515.0/25
Camera and placement13.5/156.0/15
Reflections34.0/1205.0/120
Materials and scale8.5/106.0/10
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-1017

An expressive, intricately drawn storybook scene with a complete flowing silhouette and differentiated glossy materials. The supported main lens and continuous shrimp body make the central interaction readable, but reciprocal eye lines, facial magnification and the smaller lens grip remain ambiguous. Bright granular fringes and crowded accessory lines limit the finish.

GPT-5.5

Six pale, scaled lobes form a balanced radial arrangement, but they remain separate capsules rather than an interlocking serpent knot. There are no crossings, alternating overlaps, or crisp inner bends; the central hexagon is an isolated outline. Small outward-facing heads sit within the lobes without integrated necks. Soft shading and tidy contours provide some finish, while repetitive oval scales and cartoon faces limit organic credibility.

Score breakdown

CategoryDeepSeek-V4.1-Flash-1017GPT-5.5
Task & likeness7.5/103.0/10
Anatomy & construction7.5/103.0/10
Space & placement8.0/105.0/10
Light & reflections7.0/105.0/10
Purposeful detail7.5/104.5/10
Artistry & character8.0/104.0/10
Materials & effects7.5/104.5/10
Visual integrity6.5/107.0/10

Benchmark task

DeepSeek-V4.1-Flash-1017

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.

GPT-5.5

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.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

DeepSeek-V4.1-Flash-1017

A coherent graphic interpretation with controlled contours, modeled facial volume and purposeful portrait details. Replication remains limited by the frontal pose, enlarged face, altered expression and ambiguous crossed hands. Landscape layering provides depth, while schematic fabric, smooth surfaces and tonal bands constrain the finish.

GPT-5.5

The veil, restrained smile, crossed hands and muted landscape establish Mona Lisa references. The oversized frontal face and schematic features weaken likeness and expression, while fingerless tapered hand shapes leave anatomy unresolved. Clean contours and balanced framing provide coherence, but sparse garment detail, broad landscape bands and shallow shading limit the portrait's sophistication.

Score breakdown

CategoryDeepSeek-V4.1-Flash-1017GPT-5.5
Task & likeness5.0/101.5/10
Anatomy & construction5.0/101.5/10
Space & placement6.0/101.5/10
Light & reflections6.0/102.0/10
Purposeful detail5.5/102.5/10
Artistry & character5.5/101.5/10
Materials & effects5.5/102.0/10
Visual integrity6.0/101.5/10

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-1017

A coherent, colorful beach illustration with controlled curves, clean layering and varied readable accessories. Castle details and small animal features strengthen its finish. Schematic airborne animals, uncertain board support, shallow architectural depth and decorative reflections limit physical coherence and drawing sophistication.

GPT-5.5

The sunset, palms, birds, playful animals and ball clearly establish the requested beach scene. Warm sky gradients and clean silhouettes make it appealing. Animal construction is underdeveloped: torso and limb connections are unclear, especially in the round-eared foreground figure. The dolphin lacks a convincing splash, and broad reflection bands suggest sunset light without resolving its behavior on water.

Score breakdown

CategoryDeepSeek-V4.1-Flash-1017GPT-5.5
Task & likeness7.0/107.0/10
Anatomy & construction5.5/102.5/10
Space & placement5.5/103.0/10
Light & reflections6.0/103.0/10
Purposeful detail6.5/103.0/10
Artistry & character5.0/103.0/10
Materials & effects5.5/103.0/10
Visual integrity4.5/103.5/10

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

DeepSeek-V4.1-Flash-1017

This benchmark has not been assessed yet.

GPT-5.5

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-1017

An appealing cartoon with recognizable riders, expressive faces and a cohesive twilight palette. Clean shapes support the composition, but ambiguous limb overlaps, weak seat contact and loosely resolved steering limit physical coherence. Lighting and water effects are decorative, with modest material differentiation and drawing complexity.

GPT-5.5

The raccoon's masked face, bright hull and sweeping wake make the scene readable and lively. The dog is much less resolved: its head is ambiguous, overlapping brown forms obscure its anatomy, and its paws do not visibly grip the controls. Smooth shapes and cheerful colors provide appeal, but weak steering construction and limited depth keep the drawing uneven.

Score breakdown

CategoryDeepSeek-V4.1-Flash-1017GPT-5.5
Task & likeness8.0/103.5/10
Anatomy & construction7.0/103.0/10
Space & placement7.0/104.5/10
Light & reflections6.5/105.0/10
Purposeful detail7.0/103.5/10
Artistry & character7.0/103.0/10
Materials & effects6.5/105.0/10
Visual integrity8.0/103.0/10

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-1017

An expressive, controlled illustration with continuous body construction, substantial bicycle detail and effective landscape depth. Unclear foot-to-pedal and wing-to-handlebar contacts limit physical conviction and local readability. Purposeful detail and composition are stronger than directional lighting and material treatment.

GPT-5.5

The oversized bill, bright bicycle and sunset create an appealing, recognizable cartoon. Riding mechanics are less convincing: the wing has no clear steering contact, leg attachments are uneven, and feet do not visibly engage pedals. A dark notch complicates the rear neck junction. Clean contours and orderly spokes provide polish, while simplified anatomy and lighting limit depth.

Score breakdown

CategoryDeepSeek-V4.1-Flash-1017GPT-5.5
Task & likeness8.5/107.5/10
Anatomy & construction7.0/104.5/10
Space & placement7.5/106.5/10
Light & reflections6.5/106.5/10
Purposeful detail7.5/105.5/10
Artistry & character7.0/105.0/10
Materials & effects7.0/106.0/10
Visual integrity7.5/107.5/10

Benchmark task

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