Interactive
Interactive is the live view you turn and edit in. It uses physical metals and a fast, geometry-based model of light inside stones, so it stays smooth while you work. It runs on WebGL 2, which almost every current browser has.
Render
Render traces light paths through the scene on your graphics card and refines the image pass by pass: the counter shows the passes done. Pick a quality from 64 passes for a quick look to 1,024 for a final image; 256 is the default. When the image reaches its quality, noise reduction runs on your device, lighter inside stones so facets stay sharp. Moving the camera restarts the image.
Render and Interactive model stones differently, so the two can differ slightly. Render is the reference.
Does Render need WebGPU?
The full Render needs WebGPU: a current Chrome or Edge, or Safari on macOS or iOS 26 or newer. Other browsers get a slower WebGL Render with no noise reduction, colour fire in stones, separate stone lighting, bloom, skin softening or transparent background. The status bar says which one you have. If neither is available, Interactive and its exports still work.
Are designs sent to a render farm?
Both modes run in your browser on your own hardware. No design is sent to a render farm, and no plan limits how many renders you make. A faster graphics card simply gets there sooner.