# How to open a 3MF file online

Source: https://0xr.space/m/how/open-a-3mf-file-online  
Published 2026-10-10, updated 2026-10-20, by ZeroXR, the maker of Model Explorer (https://0xr.space/).

Open 0xr.space, press Open and choose the .3mf. Its unit is read, so a part in millimetres opens at its real size, and the build plate's Z up is turned upright. Every placement in the build is drawn, so a plate holding three copies of a part shows three. Bambu Studio and OrcaSlicer projects open too. Info shows the size, the volume and whether the mesh is watertight.

Colours come only from the base materials in the file. Textures, colour groups, multi-property materials and colours painted in a slicer are not read, and those parts are drawn grey. Print settings, supports and the slice itself are not shown: this is the model, not a toolpath preview.

## Steps

1. Save or export the 3MF from your slicer or CAD tool.
2. Open 0xr.space on the computer, phone or Quest browser, press Open and choose it.
3. Open Info and read Size, Volume and Watertight.
4. Press View in your space, then Scale and 1:1 Size, to hold the part at real size before printing.

## Questions

### Is the size right?

Yes. A 3MF always says its unit, millimetres by default, and it is applied. Info gives the size in millimetres for anything under a metre.

### Why is my multicolour print grey?

Its colours are stored as textures, colour groups or slicer paint, which are not read. Colours set as base materials are shown.

### What does Watertight: No mean?

The mesh has open edges, or edges shared by three or more faces, and the count is shown. The volume is then marked with ~ as an estimate.

### Is my file uploaded?

No. It is read on the device, and nothing is sent to a server unless you create a share link yourself.

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