STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6 Astra vs MiMo-V2.6-Pro

GPT-6 Astra leads MiMo-V2.6-Pro by 26.8 points on StealthMark, 74.7 to 47.9. It leads on all 9 benchmarks. GPT-6 Astra scores higher on Newton's Mirror, with its largest category advantage in reflections.

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All results ↗
All results ↗

Overall StealthMark

74.7/100Overall rank 1/53
47.9/100Overall rank 21/53

General Intelligence

73.4/100
44.3/100

Visual Intelligence

77.0/100
54.3/100

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-6 Astra

Open or local

Open modelMIT

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6 Astra
  • MiMo-V2.6-Pro
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-6 Astra scores higher on StealthMark. MiMo-V2.6-Pro is 57× cheaper per output token and runs 1.8× faster in our speed test. Both take about 1.05M tokens of context.

  • GPT-6 Astra
  • MiMo-V2.6-Pro
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6 Astra: $50$10 inputMiMo-V2.6-Pro: $0.8757× cheaper$0.43 input
Context windowTokens per request, max output below
GPT-6 Astra: 1.05MTied128K max outputMiMo-V2.6-Pro: 1MTied128K max output
Output speedTokens per second, our measurement
GPT-6 Astra: 65tokens/sMiMo-V2.6-Pro: 1161.8× fastertokens/s
SizeTotal and active parameters
GPT-6 Astra: Not disclosedMiMo-V2.6-Pro: 1.02T42B active
Developer
OpenAIXiaomi
Released
3 Sep 202621 Sep 2026
Origin
United StatesChina
Input → output
Text, image → textText, image, video, audio → text
Architecture
Not publishedSparse Mixture-of-Experts; OpenRouter maps the route to the released Pro-RL checkpoint. The UltraSpeed edition is a separate route

Full datasheets, every price and sourceGPT-6 Astra ↗MiMo-V2.6-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 Astra 76.1/100Rank 2/47

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

MiMo-V2.6-Pro 54.6/100Rank 13/47

Survived 1 of 3
Foresight: complete playing field
Level 319 ptsTurn 20 / 20

Points per level

LevelGPT-6 AstraMiMo-V2.6-Pro
Level 1Second Thoughts
27 ptsSurvived
4 ptsOut of lives
Level 2Pressure Pot
11 ptsSurvived
9 ptsOut of lives
Level 3Hide or Flight
18 ptsSurvived
19 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 Astra 87.6/100Rank 1/48

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

MiMo-V2.6-Pro 52.6/100Rank 22/48

Cleared 5 of 5
Latch: complete playing field
Level 520.4 ptsTurn 28 / 40

Points per level

LevelGPT-6 AstraMiMo-V2.6-Pro
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10.2 ptsClearedFinished early · 1 beacon left
9 ptsClearedFinished early · 1 beacon left
Level 3Relay vault
19.2 ptsCleared
17.2 ptsClearedFinished early · 1 beacon left
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
16 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
20.6 ptsCleared
20.4 ptsCleared

Newton's Mirror

Same task instructions

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

The judgment

GPT-6 Astra

Major placement and the visible contact sequence are convincing. Dense planar light repetition, recognizable spherical panel images and simplified nested sphere motifs provide useful optical structure. Missing outer chains, truncated distant sequences and incorrect bead-like belts still leave the recursive reflections substantially incomplete.

MiMo-V2.6-Pro

The main framing and visible paint-contact story are well supported. Major optical omissions dominate the result: sparse repetitions, undersized first images, missing outer chains and absent curved nested imagery prevent a coherent mirror-room system. The metallic forms remain convincing in volume but have a soft illustrative finish.

Score breakdown

CategoryGPT-6 AstraMiMo-V2.6-Pro
State at 600 ms25.0/2523.0/25
Camera and placement15.0/1512.0/15
Reflections70.0/12019.0/120
Materials and scale10.0/107.5/10
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 Astra

The sixfold silhouette, pale coloring, outward heads and central hexagon closely match the brief. Fine scales and soft shading support rounded volume. However, several crossings have conspicuous rectangular seams and weak contact shadows, making the weave feel assembled. Small heads have limited anatomical definition, and the repetitive texture conveys less organic life than requested.

MiMo-V2.6-Pro

An appealing rabbit with balanced framing, expressive eyes and purposeful costume accents. Simple frontal construction limits anatomical and spatial accomplishment. The orange orb provides an effective luminous focal point, but unreadable wrist connections weaken the requested gestures and prevent stronger integrity credit.

Score breakdown

CategoryGPT-6 AstraMiMo-V2.6-Pro
Task & likeness9.0/106.5/10
Anatomy & construction8.0/105.0/10
Space & placement7.5/105.5/10
Light & reflections7.0/106.5/10
Purposeful detail8.0/106.5/10
Artistry & character8.5/105.0/10
Materials & effects8.0/106.5/10
Visual integrity8.5/106.0/10

Benchmark task

GPT-6 Astra

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.

MiMo-V2.6-Pro

A small rabbit in an explorer outfit floats with a luminous orb. The scene tests character anatomy, pose and the placement of geometric forms around it.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

GPT-6 Astra

The crossed hands, restrained smile, dark clothing and hazy landscape clearly recall the Mona Lisa. Replication is limited by the frontal, elongated face, schematic eyes and stiff fingers. Soft shading gives basic volume, but broad garment shapes and angular scenery lack the original’s nuanced depth and painterly transitions. The frame and composition are controlled; surface grain adds texture without resolving the simplified drawing.

MiMo-V2.6-Pro

The portrait is recognizable through its dark silhouette, slight smile and muted landscape, but replication is weak. A frontal, oversized head and symmetric torso replace the reference's turned seated pose; angular, separated hands omit its central gesture. Smooth shading maintains coherence while anatomical detail, depth and material rendering remain basic.

Score breakdown

CategoryGPT-6 AstraMiMo-V2.6-Pro
Task & likeness6.5/103.5/10
Anatomy & construction6.5/103.5/10
Space & placement6.5/104.0/10
Light & reflections6.5/105.0/10
Purposeful detail6.5/103.0/10
Artistry & character7.0/104.0/10
Materials & effects7.0/104.0/10
Visual integrity7.5/106.0/10

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 Astra

A richly composed sunset beach illustration with cohesive peach, mauve and teal colors. Sweeping palm fronds, a scalloped umbrella and curved shorelines frame the sun and its aligned reflection. Distinct animal silhouettes and carefully distributed beach details reward inspection. Simplified human and dog anatomy, slight dolphin splash cues and inconsistent equipment shadows limit physical conviction.

MiMo-V2.6-Pro

A readable sunset beach with clear requested subjects, appealing framing and purposeful accessories. Schematic anatomy, flattened foreground objects, repetitive water highlights and sparse directional shadows limit construction and physical depth. The kite's unresolved anchor also constrains integrity.

Score breakdown

CategoryGPT-6 AstraMiMo-V2.6-Pro
Task & likeness9.0/108.5/10
Anatomy & construction7.5/105.0/10
Space & placement8.5/106.0/10
Light & reflections7.5/106.5/10
Purposeful detail8.5/106.5/10
Artistry & character8.5/105.0/10
Materials & effects7.5/106.0/10
Visual integrity7.5/106.0/10

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

GPT-6 Astra

This benchmark has not been assessed yet.

MiMo-V2.6-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 Astra

Expressive animals, a balanced sunset composition and sweeping wake make an appealing illustration. The raccoon rides the dog's back, and the dog's connected foreleg reaches the controls. The compact steering assembly and layered paws are less clearly constructed. Lighting remains mostly flat, with little shadow or sun reflection. Clean contours and purposeful details support strong illustrative execution.

MiMo-V2.6-Pro

A coherent, cheerful cartoon with recognizable animals, readable steering contact and useful small details. The dog's orientation follows the craft more successfully than a wholly frontal pose would. Simple anatomy, weak raccoon grip and compressed seating contacts still limit physical credibility. Gradients and spray provide polish without resolving complex construction.

Score breakdown

CategoryGPT-6 AstraMiMo-V2.6-Pro
Task & likeness8.5/107.0/10
Anatomy & construction7.5/105.0/10
Space & placement8.0/105.5/10
Light & reflections6.5/105.5/10
Purposeful detail8.0/106.0/10
Artistry & character7.5/104.0/10
Materials & effects8.0/105.5/10
Visual integrity8.5/104.5/10

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 Astra

The pelican's long bill, flowing scarf and warm coastal palette create a charming, balanced illustration. Wheels, spokes and frame are largely coherent, but neither wing reaches the handlebars, and the rear leg's pedal contact is unclear. Flat lighting and simplified surfaces limit depth despite clean outlines and attractive feather detail.

MiMo-V2.6-Pro

The distinctive bill, continuous silhouette and detailed wheels establish a readable pelican cyclist. Shaped feathers and soft shading add character, but jointless legs, crowded pedal contacts, absent steering contact and loosely directional lighting limit the construction. The comparisons support retaining the baseline category scores.

Score breakdown

CategoryGPT-6 AstraMiMo-V2.6-Pro
Task & likeness8.0/106.5/10
Anatomy & construction7.0/105.0/10
Space & placement7.5/106.0/10
Light & reflections7.0/105.5/10
Purposeful detail8.0/106.0/10
Artistry & character8.0/106.0/10
Materials & effects7.5/105.5/10
Visual integrity8.0/106.0/10

Benchmark task

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