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OBJ File Size Reducer

Reduce an OBJ to the size you need and get an OBJ back. Groups, materials, UVs and normals are kept and UV seams locked; set the maximum MB and the result lands just under it.

📉
Drop an OBJ file here or click to browse
Up to 300 MB · OBJ (.obj)
Choose OBJ file
Or drop several files at once: 3 on the free plan, up to 25 with a Day Pass or Pro.
1
Upload OBJ
2
Set target MB
3
Download
MB
1 MB500 MB

We aim for exactly this size. Quality-preserving quadric decimation stops as soon as the file fits. If the mesh cannot be reduced further without breaking, we return the smallest safe result.

Pick an OBJ file to continue.
🔒 Files are processed on our server in isolated memory and removed within 15 minutes of your download.
Server-sideProcessed on our server, then deleted

Your file is uploaded to our server to be processed, so it does leave your device. Temporary files are removed as soon as processing finishes, and the uploaded original is deleted automatically within 120 minutes at the latest. Nothing is stored permanently.

About

OBJ files get big for one reason: they are text. Every vertex, texture coordinate, normal and face is a line of decimal numbers, so a Meshy or Tripo export, a photogrammetry scan with its texture or a sculpted Blender asset easily passes 100 MB. At that size uploads time out, Unity and Unreal take ages to import the file and web viewers stall. Converting to STL makes it smaller but throws away the texture mapping and the materials. This page keeps it an OBJ: pick a size in MB, drop the .obj, and get an .obj back that lands just under that size: between 98.5 and 100 percent of it.

What survives the reduction: object and group names (o and g), material assignments (usemtl) and the material library line (mtllib), smoothing groups, texture coordinates and normals. UV seams are locked while triangles are removed, so the texture still lands where it did. The .mtl file and the texture images never leave your computer: material names and the mtllib line do not change, so the reduced OBJ picks them up again as soon as it sits in the same folder. Coordinates are written with the precision your file already had, so the result does not grow from extra digits.

AI-generated models from Meshy, Tripo or Rodin come with a baked texture and far more triangles than they need; the reduction thins the flat areas, keeps the silhouette, and the locked seams keep the bake in place. OBJs with texture coordinates, normals or vertex colours all keep their seams locked, so game and AR assets get the budget you set per model without the texture tearing. OBJs without any of those, the usual case in 3D printing, go through the same quadric decimation as the STL Compressor and come out with the same quality. The work runs on a native C++ engine on our server, and when a target cannot be reached you get the smallest version that keeps the model intact, with the report saying so.

Files up to 300 MB upload in chunks and are deleted within 15 minutes of your download, at most 120 minutes if you never download. One OBJ up to 50 MB a day is free; a credit pack, a 24-hour pass or a subscription covers larger and further files, shared with the STL Compressor. If the OBJ is broken rather than heavy, with holes or non-manifold edges, OBJ Repair fixes it and keeps it an OBJ.

How it works

  1. 1Drop your .obj (up to 300 MB) on the upload area.
  2. 2Set the target size in MB or pick a preset.
  3. 3Start the reduction; the report shows size and triangles before and after.
  4. 4Download the reduced .obj and keep it in the folder with your .mtl and textures.

FAQ

›Do I get an OBJ back, or an STL?
An OBJ. The file is reduced in its own format: the same objects, groups, materials, smoothing groups, UVs and normals, with fewer triangles.
›Will the texture still fit after reducing?
Yes. Texture coordinates are kept and UV seams are locked while triangles are removed, so the image maps onto the surface as before. Put the reduced OBJ next to your .mtl and texture files and it finds them, because material names and the mtllib line are unchanged.
›Do I upload the .mtl and the texture images too?
No. Only the .obj is reduced. Materials and images are referenced by name and those names stay the same, so the files you already have keep working with the new OBJ.
›Why is an OBJ so much bigger than the same model as GLB?
OBJ stores everything as text, one line per vertex, UV, normal and face, while GLB stores binary numbers. A model with a million triangles, UVs and normals is often 100 MB or more as OBJ. Fewer triangles is how an OBJ gets smaller without losing its materials.
›Can I reduce a Meshy or Tripo OBJ for a game engine?
Yes. Set the size your engine or platform needs and upload the OBJ; the silhouette and the baked texture are kept while flat areas lose triangles. For a textured GLB from the same tools, use the GLB Reducer instead.
›How close to my target does it land?
Between 98.5 and 100 percent of it, never over. If even the smallest version that keeps the model intact is bigger than your target, you get that version and the result screen says the target was not reached.
›What does it cost, and are my files kept?
One OBJ up to 50 MB a day is free. A credit pack, a 24-hour pass or a subscription covers the rest and also works on the STL Compressor. Uploads are deleted within 15 minutes of the download, at most 120 minutes if nothing is downloaded.