The model runs smoothly on a work computer. On a smartphone, a loading symbol spins first and the product then stutters. Stronger compression is only one possible measure. First find out whether transfer, decoding or rendering on the device is the bottleneck.
Start by comparing file size, loading time and interaction after loading. If the smartphone still pauses with every rotation after transfer is complete, a smaller download alone is not enough.
Remove invisible detail and preserve recognisable shapes
Check which parts are visible in the intended view. A closed loudspeaker does not need detailed internal electronics for an ordinary shop view. An exploded view is different: those electronics may be its subject. Optimisation depends on the image’s purpose.
Have a working copy made. Then compare the outline, edges and important details with the original. A flat surface can tolerate simplification more readily than a clearly visible handle. Do not reduce everything by the same percentage just because the tool offers a slider.
Textures need their own review. Large areas of wood grain and a tiny label that will never be readable do not need the same resolution. Inspect the result at the maximum permitted zoom. If savings already produce a blurred surface in the normal view, they have gone too far.
Check compression and the start of loading together
Compression methods may require additional decoders. model-viewer describes these dependencies for Draco and KTX2, among others. Compare the entire first-visit transfer, not just the model file’s weight. Also record whether the browser cache was empty.
A preview image gives visitors something to see while waiting. For a model far down a long product page, decide when it should load at all. Initial product information should not have to wait for someone to open an optional 3D view.
Acceptance needs specific conditions: for example, an agreed smartphone, a named mobile-network profile and the actual shop page with its other content. Record loading time and interaction separately. That shows whether a smaller file appears sooner but remains difficult to rotate.
AR needs an additional test
If furniture is to appear in a room, check units, orientation and floor position. An armchair exported too small looks like a toy on screen. Product dimensions therefore remain alongside the AR view.
The model-viewer AR examples show output routes such as WebXR and Quick Look. Test the intended devices through their respective route all the way to placement in the room. A product image with dimensions should remain available on devices without suitable support.
Fictional acceptance case: a shelf is opened on Android and iPhone in a test environment. Both views show the approved width. Its starting position is on the floor, and a product image with dimensions remains reachable when AR is unsupported. This does not promise a millimetre-accurate fit check.
If the model already exists, work starts with web optimisation. An AR product preview additionally requires an agreed output route and suitable test devices. Keep the original and optimised export separate so later variants do not have to start from an already simplified file.