STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6 Sol vs GPT-6.1 Terra

GPT-6.1 Terra leads GPT-6 Sol by 8.7 points on StealthMark, 60.4 to 51.7. It leads on 6 of 9 benchmarks, including both games, and GPT-6 Sol on 3. 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

51.7/100Overall rank 14/54
60.4/100Overall rank 9/54

General Intelligence

46.1/100
58.0/100

Visual Intelligence

61.6/100
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 Sol

BENCHMARK BY BENCHMARK

Where each model leads

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

DATASHEET

Specs and pricing

GPT-6.1 Terra scores higher on StealthMark and is 2× cheaper per output token. Both take about 1.05M tokens of context.

  • GPT-6 Sol
  • GPT-6.1 Terra
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6 Sol: $10$2 inputGPT-6.1 Terra: $52× cheaper$1 input
Context windowTokens per request, max output below
GPT-6 Sol: 1.05MTied128K max outputGPT-6.1 Terra: 1.05MTied128K max output
Output speedTokens per second, our measurement
GPT-6 Sol: 91tokens/sGPT-6.1 Terra: Not measured
Developer
OpenAIBoth
Released
22 Sep 202626 Oct 2026
Origin
United StatesBoth
Input → output
Text, image → textBoth

Full datasheets, every price and sourceGPT-6 Sol ↗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 Sol 30.4/100Rank 29/50

Survived 0 of 3
Foresight: complete playing field
Level 36 ptsTurn 7 / 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 SolGPT-6.1 Terra
Level 1Second Thoughts
17 ptsOut of lives
21 ptsSurvived
Level 2Pressure Pot
5 ptsOut of lives
9 ptsOut of lives
Level 3Hide or Flight
6 ptsOut of lives
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 Sol 76.6/100Rank 13/51

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 SolGPT-6.1 Terra
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.6 ptsCleared
9.8 ptsCleared
Level 3Relay vault
18.4 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 Sol

The centered sphere, separate airborne black form and color ordering support scene recognition. Rounded shading and curved rims provide readable volume and gloss. Shrinking side images, a floor counterpart and curved lamp highlights provide isolated reflection cues, but broad bands and sparse repetitions leave nested room imagery, outer chains and ordered emitter mapping unsupported. Vertical framing departs from the prescribed view, while paint contact, transport and solid-metal appearance remain weak or uncertain.

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 SolGPT-6.1 Terra
State at 600 ms19.0/2523.0/25
Camera and placement12.0/1511.0/15
Reflections8.0/12033.0/120
Materials and scale6.5/107.5/10
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 Sol

Six evenly spaced lobes, small outward-facing heads and a regular hexagonal opening make the motif immediately readable. The central angular band merges several intersections, weakening the alternating weave. Pale shading gives modest volume, but scales are sparse and repetitive, crossing shadows are weak, and the heads have limited anatomical definition.

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 SolGPT-6.1 Terra
Task & likeness7.5/107.5/10
Anatomy & construction6.5/106.5/10
Space & placement6.5/106.5/10
Light & reflections6.0/106.0/10
Purposeful detail6.5/106.5/10
Artistry & character7.0/106.5/10
Materials & effects5.5/106.0/10
Visual integrity6.0/106.0/10

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 Sol

The dark clothing, crossed arms, restrained smile and distant landscape establish the Mona Lisa reference. Replication is limited by the oversized, nearly frontal head, schematic eyes and fingerless hand shapes. Soft shading suggests facial volume, but muddy transitions and angular scenery weaken depth and painterly finish.

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 SolGPT-6.1 Terra
Task & likeness5.5/105.5/10
Anatomy & construction3.5/106.5/10
Space & placement5.5/104.5/10
Light & reflections6.0/106.5/10
Purposeful detail4.5/106.0/10
Artistry & character5.0/106.0/10
Materials & effects4.5/106.0/10
Visual integrity6.0/106.5/10

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 Sol

A cohesive, appealing beach illustration with framing palms, a warm sunset and a clear reflection path. The turtle, crab, birds and beach ball fulfill the playful brief. Clean silhouettes and restrained colors work well, while simplified anatomy, shallow spatial cues and inconsistent foreground shadows limit depth and finish.

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 SolGPT-6.1 Terra
Task & likeness8.5/108.5/10
Anatomy & construction7.0/107.5/10
Space & placement7.0/106.5/10
Light & reflections6.5/105.5/10
Purposeful detail7.0/107.5/10
Artistry & character6.0/107.0/10
Materials & effects6.5/106.5/10
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 Sol

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 Sol

The raccoon rides the dog's back, and the dog's connected foreleg reaches the steering grip. Expressive faces, a cohesive palette and sweeping wake make an appealing illustration. Vehicle construction and seating remain simplified; broad splash ribbons convey speed more convincingly than physical displacement. The sun has little corresponding reflection or effect on the subjects.

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 SolGPT-6.1 Terra
Task & likeness7.5/106.5/10
Anatomy & construction6.5/105.5/10
Space & placement7.5/106.0/10
Light & reflections6.0/105.0/10
Purposeful detail7.5/107.0/10
Artistry & character6.5/106.0/10
Materials & effects7.5/106.0/10
Visual integrity8.0/107.0/10

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 Sol

The pelican reads clearly, with an expressive face, generous bill and appealing pastel composition. Spokes, basket weave and feather contours are carefully organized. Both legs connect to the body, though joint definition and pedal contacts are simplified. Consistent wheel placement and a ground shadow establish support; restrained shading gives limited volume.

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 SolGPT-6.1 Terra
Task & likeness9.0/107.0/10
Anatomy & construction7.5/107.0/10
Space & placement8.0/106.0/10
Light & reflections7.0/105.5/10
Purposeful detail8.0/107.0/10
Artistry & character8.5/106.5/10
Materials & effects7.0/105.5/10
Visual integrity8.5/106.0/10

Benchmark task

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