STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6 Astra vs GPT-6.1 Terra

GPT-6 Astra leads GPT-6.1 Terra by 14.3 points on StealthMark, 74.7 to 60.4. 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 1/54
60.4/100Overall rank 9/54

General Intelligence

73.4/100
58.0/100

Visual Intelligence

77.0/100
64.9/100

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

  • GPT-6 Astra

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6 Astra
  • GPT-6.1 Terra
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-6 Astra scores higher on StealthMark. GPT-6.1 Terra is 10× cheaper per output token. Both take about 1.05M tokens of context.

  • GPT-6 Astra
  • GPT-6.1 Terra
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6 Astra: $50$10 inputGPT-6.1 Terra: $510× cheaper$1 input
Context windowTokens per request, max output below
GPT-6 Astra: 1.05MTied128K max outputGPT-6.1 Terra: 1.05MTied128K max output
Output speedTokens per second, our measurement
GPT-6 Astra: 65tokens/sGPT-6.1 Terra: Not measured
Developer
OpenAIBoth
Released
3 Sep 202626 Oct 2026
Origin
United StatesBoth
Input → output
Text, image → textBoth

Full datasheets, every price and sourceGPT-6 Astra ↗GPT-6.1 Terra ↗

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 2/50

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

GPT-6.1 Terra 62.0/100Rank 9/50

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

Points per level

LevelGPT-6 AstraGPT-6.1 Terra
Level 1Second Thoughts
27 ptsSurvived
21 ptsSurvived
Level 2Pressure Pot
11 ptsSurvived
9 ptsOut of lives
Level 3Hide or Flight
18 ptsSurvived
15 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 1/51

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

GPT-6.1 Terra 77.7/100Rank 12/51

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

Points per level

LevelGPT-6 AstraGPT-6.1 Terra
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
10.2 ptsClearedFinished early · 1 beacon left
9.8 ptsCleared
Level 3Relay vault
19.2 ptsCleared
19.2 ptsCleared
Level 4Passing bay
18.2 ptsClearedFinished early · 3 beacons left
17.8 ptsClearedFinished early · 3 beacons left
Level 5Second thoughts
20.6 ptsCleared
20.6 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.

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.

Score breakdown

CategoryGPT-6 AstraGPT-6.1 Terra
State at 600 ms25.0/2523.0/25
Camera and placement15.0/1511.0/15
Reflections70.0/12033.0/120
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

Same 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.

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.

Score breakdown

CategoryGPT-6 AstraGPT-6.1 Terra
Task & likeness9.0/107.5/10
Anatomy & construction8.0/106.5/10
Space & placement7.5/106.5/10
Light & reflections7.0/106.0/10
Purposeful detail8.0/106.5/10
Artistry & character8.5/106.5/10
Materials & effects8.0/106.0/10
Visual integrity8.5/106.0/10

Benchmark task

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

Same 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.

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.

Score breakdown

CategoryGPT-6 AstraGPT-6.1 Terra
Task & likeness6.5/105.5/10
Anatomy & construction6.5/106.5/10
Space & placement6.5/104.5/10
Light & reflections6.5/106.5/10
Purposeful detail6.5/106.0/10
Artistry & character7.0/106.0/10
Materials & effects7.0/106.0/10
Visual integrity7.5/106.5/10

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 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.

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.

Score breakdown

CategoryGPT-6 AstraGPT-6.1 Terra
Task & likeness9.0/108.5/10
Anatomy & construction7.5/107.5/10
Space & placement8.5/106.5/10
Light & reflections7.5/105.5/10
Purposeful detail8.5/107.5/10
Artistry & character8.5/107.0/10
Materials & effects7.5/106.5/10
Visual integrity7.5/107.5/10

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

GPT-6 Astra

This benchmark has not been assessed yet.

GPT-6.1 Terra

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.

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.

Score breakdown

CategoryGPT-6 AstraGPT-6.1 Terra
Task & likeness8.5/106.5/10
Anatomy & construction7.5/105.5/10
Space & placement8.0/106.0/10
Light & reflections6.5/105.0/10
Purposeful detail8.0/107.0/10
Artistry & character7.5/106.0/10
Materials & effects8.0/106.0/10
Visual integrity8.5/107.0/10

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

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.

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.

Score breakdown

CategoryGPT-6 AstraGPT-6.1 Terra
Task & likeness8.0/107.0/10
Anatomy & construction7.0/107.0/10
Space & placement7.5/106.0/10
Light & reflections7.0/105.5/10
Purposeful detail8.0/107.0/10
Artistry & character8.0/106.5/10
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.