Free OBJ Editor — Edit OBJ Files Online

Edit OBJ files online, free. Fix a .obj to exact millimetres, cut and combine it with parametric shapes, hollow it, repair the mesh and export STL, 3MF or DXF.

Edit OBJ files online — really edit them.

Most online OBJ tools let you spin the model and stop there. Drop a .obj here and you get a full CAD editor: exact millimetre dimensions, booleans against real shapes, hollowing, mesh repair and a print check, then export whatever your slicer wants.

Free to use · Runs in your browser · Start without an account

An editor, not another viewer

OBJ is the format that comes out of every sculpting and scanning tool, and the one that usually needs work before it prints.

Open any OBJ instantly

Drag a .obj onto the build plate and it renders straight away — your browser reads the file itself, so there is no upload queue and nothing to wait for before you see it.

Fix the scale for good

OBJ records no units, so a model exported at scene scale can arrive wildly off. Reinterpret the file as millimetres, centimetres, inches or metres in one tap, with the resulting dimensions previewed before you accept, then type exact values.

Cut and combine with real shapes

Boolean union, subtract, and intersect your OBJ against parametric primitives: add a mounting tab, cut a cable hole, flatten a base, or merge two pieces into one printable body. Non-destructive and fully undoable.

Hollow, lighten, and estimate

Shell a solid model to a set wall thickness and add drainage holes, then see what the result will weigh and cost in filament, so you can tell exactly what the hollowing saved before you slice.

Measure what you were sent

Measure edge lengths, hole radii and diameters, true arc lengths, face areas, angles, and the smallest gap between two parts: the numbers you need to make something fit a model you did not draw.

Export for any slicer or tool

Save print-ready STL or 3MF, OBJ or GLB for other 3D software, and SVG or DXF of a 2D projection for a laser cutter. Clean, welded geometry, repaired before it reaches your slicer.

Drop in an OBJ and start editing

No download, no account needed, and your work saves in the browser as you go.

What happens to your file

It opens on your device, it is saved to your workspace as you work, and it exports back out in the format your slicer wants.

No upload queue

Your browser reads and renders the model itself, so it appears as soon as you drop it in — you are never queued behind anyone else’s upload, and the file does not travel anywhere before you can see it.

Saved, not discarded

Most online viewers forget your file the moment you close the tab. OwlCAD keeps the model in your own workspace and syncs it as you work, so it is still there when you come back to this browser. Create a free account and it follows you to any device, and your projects dashboard lets you delete anything you no longer want.

Exports to a real file

When you are done, export STL, 3MF, OBJ, GLB or STEP — the format your slicer or your colleague actually needs, not a project file that only opens here.

Frequently asked questions

Can I edit an OBJ file online without installing anything?

Yes. Drag a .obj onto the build plate and it opens in a full browser CAD editor — not just a viewer. Scale it to exact millimetres, cut and combine it with parametric shapes, hollow it, repair the mesh, and export it again. No install, and no account needed to start.

Is my OBJ uploaded to a server?

Your browser reads and renders it, so it is on screen before anything is sent anywhere. It is then saved to your workspace, which syncs to OwlCAD’s storage — including for a guest session — so the model is still there when you come back. Sign in and it follows you to any device; delete it from your projects dashboard whenever you want.

My OBJ opened at the wrong size — can I fix it?

Yes. OBJ records no units, so a model authored in metres or at a scene scale can arrive far too large or small. The bar shown on import reinterprets the file as millimetres, centimetres, inches, or metres in one tap and previews the resulting dimensions each time, so you can see which reading is right before accepting it. You can also type exact dimensions afterwards.

What can I export an OBJ to?

STL, 3MF, OBJ, and GLB for meshes, plus SVG and DXF for 2D projections. A part you rebuild parametrically in OwlCAD can also export as solid STEP; an imported OBJ mesh exports to STEP as a faceted shell — a valid solid, but without analytic surfaces to edit in mechanical CAD.

Does it keep the colours from my OBJ?

OwlCAD reads the geometry and per-vertex colours where the file carries them. Texture maps and .mtl material libraries are not applied — for 3D printing, the shape and its dimensions are what matter, and a model imports uncoloured rather than wrongly coloured.

Is the OBJ editor free?

Yes. Importing, editing, repairing, and exporting are free forever, with no watermark and no export limit. Only AI generation is part of OwlCAD Pro.

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