3DS to OBJ converter

For about fifteen years, .3ds was the common exchange format of 3D. Model libraries, CD-ROM collections, game mods, architecture visualisations and university projects from the 1990s and 2000s are full of 3DS files, and many of those models exist in no other format. Modern software support for 3DS is patchy: some programs dropped their importer, others need an add-on. OBJ, by contrast, opens everywhere. This 3DS to OBJ converter reads the old binary format and writes a clean OBJ, with every 3DS object as a named object and coordinates in the style your software expects.

How to convert 3DS to OBJ

1. Drop the .3ds file on the box.
2. Check the preview. The size is shown with the 3DS numbers read as millimetres, together with the triangle count and the number of objects.
3. Fix the size if needed with Source units under More options. Old models were made in all sorts of units.
4. Choose the OBJ coordinates: Z up, millimetres (default) keeps the numbers as they are; Y up, metres suits Blender, Unity and other Y-up programs.
5. Download the OBJ.

Objects, names and the 65,535 limit

Inside a 3DS file, a model is a list of named objects, each with its own vertex and face list. Those counts are 16-bit numbers, so no object can have more than 65,535 vertices or faces. Detailed models were therefore split into many objects, often with short, cryptic names like "WHEEL01" or "BODY_L". The converter keeps every object as its own o object in the OBJ, with its name, so the structure of the original model survives. OBJ has no such limit, so in your 3D program you can join the pieces into one mesh if you prefer.

3DS stores each corner once and refers to it from the faces, and the OBJ does the same, which keeps both compact and lets smooth shading work in modern programs. The demo gear is 15 KB as 3DS and 26 KB as OBJ, the difference being only binary versus text.

Units and orientation

3D Studio had a unit setting, but many 3DS exporters didn't store it, or stored something that doesn't match the numbers. The converter reads the numbers as millimetres and shows the result; if a car comes out 4.5 mm long, it was modelled in metres, so choose Metres in Source units. 3D Studio and 3ds Max use Z as up, like CAD and printers, so with Z up, millimetres the OBJ keeps the original orientation. With Y up, metres, the model is turned to stand upright in Y-up programs and written at real size in metres, once the source unit is right.

Materials and textures

3DS files carry materials that reference texture images by 8.3 DOS file names, such as BRICK04.JPG. Those images were often lost when collections were copied, and the OBJ written here contains the shape only, without a material file. Rebuilding materials in a modern program is usually worth it anyway, because 3D Studio's old shading model doesn't match today's physically based materials. If you have the original texture images, apply them to the objects by name after importing.

Related conversions

For 3D printing, the 3DS to STL converter makes a print file directly. For the web and AR, the GLB button in the Same file as row writes a GLB. Have models in other old formats? The 3D model converter reads thirteen formats.

Importing the OBJ into Blender

Choose Y up, metres before downloading, and set Source units to whatever the 3DS was really made in: Millimetres if the size line already looks right, Metres for most architecture and vehicle models. Then use File → Import → Wavefront (.obj) in Blender with the default settings. Every 3DS object arrives as its own Blender object, named as in the 3DS file, at real size and standing upright. With Z up, millimetres instead, set Forward to Y and Up to Z in the import dialog, and a scale of 0.001.

After importing, check the normals: some old exporters wrote faces in mixed order, which shows up as dark or see-through patches. In Edit Mode, select everything and use Mesh → Normals → Recalculate Outside. Duplicate vertices along object seams can be merged with Merge by Distance.

Converting a whole library

Converting one file at a time works well for a handful of models. For a large collection, sort the files first: keep the models you will actually use, check one or two to learn which unit the collection was made in, and then use the same Source units setting for all of them, so the converted library is consistent. The converter keeps your settings while the page is open, so you can drop one file after another.

Updated November 2026 · How these tools work