STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Terra vs MiMo-V2.6-Flash

GPT-6.1 Terra leads MiMo-V2.6-Flash by 15.8 points on StealthMark, 60.4 to 44.6. It leads on 7 of 9 benchmarks, including both games, and MiMo-V2.6-Flash on 2. GPT-6.1 Terra scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

60.4/100Overall rank 9/54
44.6/100Overall rank 29/54

General Intelligence

58.0/100
41.0/100

Visual Intelligence

64.9/100
49.8/100

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

  • GPT-6.1 Terra
  • MiMo-V2.6-Flash
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-6.1 Terra scores higher on StealthMark. MiMo-V2.6-Flash is 18× cheaper per output token. Both take about 1.05M tokens of context.

  • GPT-6.1 Terra
  • MiMo-V2.6-Flash
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Terra: $5$1 inputMiMo-V2.6-Flash: $0.2818× cheaper$0.14 input
Context windowTokens per request, max output below
GPT-6.1 Terra: 1.05MTied128K max outputMiMo-V2.6-Flash: 1MTied128K max output
Output speedTokens per second, our measurement
GPT-6.1 Terra: Not measuredMiMo-V2.6-Flash: 547tokens/s
SizeTotal and active parameters
GPT-6.1 Terra: Not disclosedMiMo-V2.6-Flash: 309B15B active
Developer
OpenAIXiaomi
Released
26 Oct 202621 Sep 2026
Origin
United StatesChina
Input → output
Text, image → textText, image, video, audio → text
Architecture
Not publishedReleased Flash-RL checkpoint: sparse Mixture-of-Experts; hosted Flash and MOPD variants are distinct artifacts

Full datasheets, every price and sourceGPT-6.1 Terra ↗MiMo-V2.6-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.

GPT-6.1 Terra 62.0/100Rank 9/50

Survived 2 of 3
Foresight: complete playing field
Level 315 ptsTurn 20 / 20

MiMo-V2.6-Flash 71.3/100Rank 38/501 of 3 levels

1 of 3 played
Foresight: complete playing field
Level 212 ptsTurn 14 / 18

Points per level

LevelGPT-6.1 TerraMiMo-V2.6-Flash
Level 1Second Thoughts
21 ptsSurvived
Pending
Level 2Pressure Pot
9 ptsOut of lives
12 ptsOut of lives
Level 3Hide or Flight
15 ptsSurvived
Not played

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-6.1 Terra 77.7/100Rank 12/51

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

MiMo-V2.6-Flash 66.3/100Rank 30/513 of 5 levels

3 of 5 played
Latch: complete playing field
Level 318 ptsTurn 36 / 36

Points per level

LevelGPT-6.1 TerraMiMo-V2.6-Flash
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
9.6 ptsCleared
Level 3Relay vault
19.2 ptsCleared
18 ptsCleared
Level 4Passing bay
17.8 ptsClearedFinished early · 3 beacons left
Pending
Level 5Second thoughts
20.6 ptsCleared
Not played

Newton's Mirror

Same task instructions

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

The judgment

GPT-6.1 Terra

The sphere, airborne black and first reflected silhouettes preserve important geometry within the portrait frame. Paint deformation, contact order and forward transport are supported, with a small crimson endpoint overshoot. Major optical omissions dominate: short finite reflection sequences and smooth bands replace extensive, spatially ordered mirror imagery. Dark gloss and crisp upper emitter shapes provide partial material credit.

MiMo-V2.6-Flash

The faint lower sphere image provides limited reflection evidence through reversed paint-color ordering. The wider reflection system and nested room imagery are absent. The colored beads do not resolve the required impact and transport history, while displaced paint positions and weak material rendering further limit the result.

Score breakdown

CategoryGPT-6.1 TerraMiMo-V2.6-Flash
State at 600 ms23.0/255.0/25
Camera and placement11.0/154.5/15
Reflections33.0/1206.5/120
Materials and scale7.5/102.5/10
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-6.1 Terra

A balanced serpent emblem with six attached outward heads, delicate scales and softly rounded bodies. Its compact silhouette reads clearly, but central routing does not establish every alternating crossing or crisp inward corner. Repetitive texture, limited facial anatomy and weak contact shadows constrain its organic character.

MiMo-V2.6-Flash

The centered rabbit has an appealing alert expression, a balanced silhouette, and a restrained technological palette. Outfit panels and orbital accents are cleanly resolved. The orb-holding paw has an ambiguous grip, the ears lack distinct angular bends, and the halo's interlocking construction is unclear. Soft shading suggests volume, but materials and spatial depth remain simplified.

Score breakdown

CategoryGPT-6.1 TerraMiMo-V2.6-Flash
Task & likeness7.5/108.0/10
Anatomy & construction6.5/106.5/10
Space & placement6.5/107.0/10
Light & reflections6.0/107.0/10
Purposeful detail6.5/106.0/10
Artistry & character6.5/105.5/10
Materials & effects6.0/106.5/10
Visual integrity6.0/108.0/10

Benchmark task

GPT-6.1 Terra

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-Flash

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-6.1 Terra

A recognizable interpretation with developed facial shading, shaped sleeve folds and purposeful small features. These strengths support modest upward calibration, while the frontal torso, elongated proportions, schematic finger joints and unresolved seated support keep replication and construction uneven.

MiMo-V2.6-Flash

The dark clothing, long hair, folded hands and hazy landscape make the reference recognizable. Replication is limited by the frontal symmetry, elongated face, wide staring eyes and downturned mouth. Both arms connect to the hands, but the overlapping palms and looplike fingers are poorly resolved. Soft facial shading provides some volume; the clothing and landscape remain broad, simplified shapes.

Score breakdown

CategoryGPT-6.1 TerraMiMo-V2.6-Flash
Task & likeness5.5/103.0/10
Anatomy & construction6.5/102.5/10
Space & placement4.5/104.0/10
Light & reflections6.5/103.0/10
Purposeful detail6.0/104.0/10
Artistry & character6.0/102.5/10
Materials & effects6.0/103.5/10
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

GPT-6.1 Terra

A coherent sunset illustration with clear prompt fulfillment, controlled framing and varied, purposeful small details. Simplified joints, frontal staging, flattened animal forms and weakly directional shadows limit its anatomical, spatial and physical sophistication.

MiMo-V2.6-Flash

The warm sunset, aligned reflection, framing palms and playful beach animals create an appealing, coherent scene. Small toys and shells remain readable. Drawing is simplified: animals have limited volume, water uses repetitive horizontal strokes, and foreground shadows do not consistently follow the central sun. Clean execution supports a competent illustration, but depth and material rendering remain modest.

Score breakdown

CategoryGPT-6.1 TerraMiMo-V2.6-Flash
Task & likeness8.5/107.5/10
Anatomy & construction7.5/106.5/10
Space & placement6.5/107.0/10
Light & reflections5.5/106.0/10
Purposeful detail7.5/107.0/10
Artistry & character7.0/106.0/10
Materials & effects6.5/106.0/10
Visual integrity7.5/108.0/10

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-6.1 Terra

This benchmark has not been assessed yet.

MiMo-V2.6-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

GPT-6.1 Terra

A coherent cartoon with expressive animals, readable steering and a clear wake. Fine facial and hull details reward inspection. The main limits are the boatlike craft, simplified joints, weakly braced frontal raccoon and minimal directional lighting or material depth.

MiMo-V2.6-Flash

The raccoon riding the dog reads clearly, with expressive faces and a cheerful waterscape. The steering action is weak: no paw reaches the handlebar, which meets the dog's muzzle. The vehicle resembles a thin board with a steering post. Overlapping limbs obscure anatomy, while limited shadows, reflections and surface modeling keep the scene flat.

Score breakdown

CategoryGPT-6.1 TerraMiMo-V2.6-Flash
Task & likeness6.5/106.5/10
Anatomy & construction5.5/104.0/10
Space & placement6.0/106.5/10
Light & reflections5.0/104.5/10
Purposeful detail7.0/105.5/10
Artistry & character6.0/104.0/10
Materials & effects6.0/105.5/10
Visual integrity7.0/106.0/10

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-6.1 Terra

A coherent pelican cyclist with expressive proportions, purposeful feather detail and developed bicycle machinery. Continuous body contours, aligned wheels and readable pedal contacts support the scene. Simplified articulation, shallow modelling and an unresolved steering connection limit construction and placement.

MiMo-V2.6-Flash

The pelican is immediately recognizable, with an expressive eye and prominent pouch, and the landscape provides clear framing. Clean outlines and spokes support the cheerful illustration. Both feet visibly miss the bicycle's pedal mechanism, weakening the riding action. Simplified machinery, shallow depth and loosely directional shading limit the requested masterpiece quality.

Score breakdown

CategoryGPT-6.1 TerraMiMo-V2.6-Flash
Task & likeness7.0/108.0/10
Anatomy & construction7.0/105.5/10
Space & placement6.0/107.0/10
Light & reflections5.5/106.0/10
Purposeful detail7.0/107.0/10
Artistry & character6.5/106.5/10
Materials & effects5.5/105.5/10
Visual integrity6.0/107.5/10

Benchmark task

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