AnyFormat

00 3MF → OBJ

3MF to OBJ

Each 3MF object becomes a named OBJ group.

Drop files or a folder here

or choose from your device · paste with ⌘V / Ctrl+V

.3mf

03Options 2

glTF works in metres and the printing formats in millimetres. Leave this on unless your model comes out a thousand times the wrong size.

Multiplied on top of any unit conversion. Use 25.4 to turn inches into millimetres.

  • No upload The conversion runs in this tab. Your file never travels — not to us, and not to the advertising.
  • No sign-up, no email, no daily cap There is no account system to sign up to.
  • No size limit we invented Only your device's memory — about ~2 GB on a desktop browser, ~400 MB on a phone.
  • Turn your Wi-Fi off and convert anyway The conversion needs nothing but this page. Ads will not load without a connection; your file will still convert. That is the whole claim, and it takes five seconds to check.

Converts 3MF to OBJ — the usual route into a 3D application rather than a slicer. OBJ keeps named objects, so a multi-part 3MF stays multi-part.

Names and structure survive

Each object in the 3MF becomes an o group in the OBJ with its original name. That is the main reason to choose OBJ over STL here: a build plate of six labelled parts arrives as six labelled parts rather than one anonymous mesh.

Vertex indexing carries over directly too, since both formats index rather than repeat.

What does not

Colour and materials. 3MF stores them; standard OBJ puts materials in a separate .mtl file and has no per-vertex colour at all. Convert to PLY if per-vertex colour is what you need, or to glTF if you want materials.

Units, and the thousand-fold mistake

Neither STL nor OBJ records a unit. A file containing the number 10 might mean 10 mm, 10 cm or 10 inches, and nothing in the file says which. Slicers assume millimetres, CAD packages usually assume whatever the document was set to, and glTF viewers assume metres.

That last one is the trap. glTF's convention is metres; the printing formats are millimetres. Convert between them without scaling and your model arrives either a thousand times too small or a thousand times too large. Automatic unit conversion handles it, and the note tells you what was applied so you can switch it off when the source was already in the other unit.

The bounding box is reported after every conversion. Checking it against what you expect takes two seconds and catches this immediately.

Other names for this

Also searched as “3mf to wavefront obj”.

Questions

Are my object names kept?
Yes, as OBJ group names. This is the main advantage over converting to STL.
What happened to the colours?
OBJ has no per-vertex colour and keeps materials in a separate .mtl. Use PLY for vertex colour or glTF for materials.
Is my model uploaded?
No. The parsing and rewriting happen in this tab. Models are frequently confidential — an unreleased product, a client’s part, a scan of something proprietary — and none of it is transmitted. Turn your Wi-Fi off and the tool keeps working.
Can I convert several models at once?
Yes — drop as many as you like, or a whole folder. Each keeps its original name with the new extension, and you can download them individually or as a ZIP.