GPT-6.1 Terra vs Claude Opus 5.5 vs Claude Haiku 5.5
OpenAI's new cheap and fast model against the best and the smallest Claude you can buy. Same four prompts, word for word, one run each: a flying train, an animal cell in SVG, a voxel rocket launch and a floating treasure tower. Cards that needed a fix say so. Everything runs in your browser.
Steam train in the sky
A Three.js train flying between floating islands above a sea of clouds: cameras, night, speed.
A locomotive and three carriages on a curving rail between floating islands: smoke, lit windows, sunset or starry night, three cameras, speed slider.
Sunset sky, smoke and a glowing rail; simpler islands, a very good night view.
Starts with the camera on a green hill, and the carriages do not follow the rail well. It runs, night mode works.
Animal cell in SVG
A scientifically accurate, living animal cell: hover, click to zoom, labels with leader lines.
Labels with leader lines, an explanation panel for every organelle, click to zoom, reset. Everything works.
More organelles and cytoskeleton lines; labels and click-to-zoom work.
As written it did not start: a ternary used as the target of +=, so the whole script stops. One marked fix; original kept. Original: cell-haiku-original/
Voxel rocket launch
A Minecraft-style spaceport: countdown, ignition, liftoff, stage separation, day and night.
Spaceport by the sea: 10-second countdown, ignition, liftoff, camera follows the rocket, day/night.
Bigger island, a clear launch sequence with a big smoke cloud at liftoff, night sky behind the flame.
As written the animation stopped: the particle mesh had no colour buffer yet. One marked fix; original kept. Original: rocket-haiku-original/
Floating treasure tower
A voxel tower on a floating island with waterfalls, crystals, birds and a chest that opens.
Stone blocks, a flag, vines, waterfalls into the void; torches and crystals light it at night; the chest opens.
A darker tower with glowing crystals and a starry night; the chest opens with light.
Simpler shapes, but it works: birds, waterfalls, and the chest bursts with light.
Time and cost per build
All three through OpenRouter on October 27, 2026. GPT-6.1 Terra: reasoning effort medium. Opus 5.5 and Haiku 5.5: reasoning effort low (on medium both sometimes think until the output limit and return nothing on builds this size). Cost = what OpenRouter charged.
| Model | Build | Time | Output tokens | Cost | Fixes |
|---|---|---|---|---|---|
| GPT-6.1 Terra | Steam train in the sky | 1.7 min | 8,968 | $0.05 | - |
| Claude Opus 5.5 | Steam train in the sky | 1.1 min | 8,832 | $0.18 | - |
| Claude Haiku 5.5 | Steam train in the sky | 2.8 min | 39,413 | $0.02 | - |
| GPT-6.1 Terra | Animal cell in SVG | 2.1 min | 11,170 | $0.06 | - |
| Claude Opus 5.5 | Animal cell in SVG | 1.0 min | 7,489 | $0.15 | - |
| Claude Haiku 5.5 | Animal cell in SVG | 1.9 min | 25,952 | $0.01 | 1 (marked) |
| GPT-6.1 Terra | Voxel rocket launch | 1.8 min | 9,510 | $0.05 | - |
| Claude Opus 5.5 | Voxel rocket launch | 1.0 min | 7,468 | $0.15 | - |
| Claude Haiku 5.5 | Voxel rocket launch | 4.3 min | 57,331 | $0.03 | 1 (marked) |
| GPT-6.1 Terra | Floating treasure tower | 2.0 min | 10,882 | $0.05 | - |
| Claude Opus 5.5 | Floating treasure tower | 1.1 min | 8,079 | $0.16 | - |
| Claude Haiku 5.5 | Floating treasure tower | 4.3 min | 58,007 | $0.03 | - |
The exact prompts are for Ruocco Academy members. The Academy is not open yet: join the waiting list and you get one email when it opens. The demos on this page are free to use for everyone.
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