Browser-local viewer

3MF viewer

Open a 3MF package and inspect it locally. 3MF is the one common maker format that records its own unit, so unlike an STL the dimensions shown here are the real ones rather than a convention someone had to assume.

Drop your 3MF files here

STL, OBJ, PLY, GLB, glTF, 3MF, SVG and DXF. Nothing is uploaded: files are read and inspected inside this tab. Checking what this device can handle...

Queue

No files yet. Drop models above, or use the file picker.

Add a model to see it here.

Inspection

Add a model to see its dimensions, mesh health and estimated volume.

Output

Convert toDXF and SVG need a 2D source. A mesh cannot become a drawing without choosing a projection, which is yours to decide, not ours to guess.Encoding

Units

Assign unitLabel the existing numbers. Nothing is rescaled.Convert unitRescales so the physical size stays the same.

Size and placement

ScalingOrientation

Rotate X°Rotate Y°Rotate Z°

Centre on bedCentres X and Y, and sits the model on Z=0.

Repair and cleanup

These can change the shape, so they need a before-and-after review before export.

Safe repairWelds duplicates, drops zero-area triangles and fixes winding. Never fills holes.Weld duplicate verticesRemove zero-area trianglesWeld tolerance

Vertices closer than this are merged.Merge all meshes into oneNormals

Convert or repair this file as well

What this 3MF viewer shows and what it does not

Objects are placed using the transforms in the build section, and nested components are resolved, so what you see matches what a slicer would place.
Base materials and display colours are read and listed. Textures are not: 3MF core materials are flat colours, and no image is ever loaded.
3MF extensions beyond the core specification, including production, slice and beam-lattice data, are not interpreted, and anything skipped is reported.
A 3MF is a ZIP archive and is treated as untrusted input: entry counts, declared sizes, compression ratios and entry paths are all checked before anything is decompressed.
Per-vertex colour is detected and reported but not rendered as vertex colour today.

Troubleshooting

The 3MF will not open

It must be a complete .3mf package rather than the 3dmodel.model XML on its own. A hand-re-zipped archive is often missing its relationship part; re-export from the original tool.

Only part of the assembly is shown

Only objects referenced by a build item are placed, which is what the specification requires. If the file declares objects but no build items, all of them are shown and you are told that happened.

The colours look different from my slicer

Display colours are read as written. Slicers apply their own preview shading and colour management, so an exact match is not expected.

Is it safe to open a 3MF from a stranger?

It is opened defensively. Zip bombs, path traversal, absurd entry counts and XML entity attacks are all refused before any expensive work happens, and nothing is written to your filesystem.

Questions

Why are 3MF dimensions more trustworthy than STL ones?

Because 3MF states its unit in the file. An STL is bare numbers, so any viewer has to guess what they mean; a 3MF tells you, and this page shows you which it read.

Is the file uploaded anywhere?

No. Reading, rendering and inspection all happen in a Web Worker in this tab. There is no code path in the project that could send a file anywhere.

Can I see what converting it to STL would lose?

Yes. The workspace lists exactly what a target format cannot carry — materials, units, object separation — before you export anything.