3dfileconverter.online

Resize STL Online

Resize STL, OBJ or STEP models locally using a target X dimension or scale percentage. Rotate, center and export your model with the selected transforms.

Enable JavaScript to open a model and use the interactive workspace.

How do I use this tool?

  1. Choose an OBJ, STL or STEP model from your device.
  2. Preview your model and adjust the settings.
  3. Create your output and download the result.

What does this tool do?

Set a target X dimension for uniform scaling, or enter a scale percentage. Rotations are applied in X, Y, Z order. Centering moves the bounding-box center to the origin. All transforms are included in the export.

What are the file limits?

Models are processed locally. Inputs are limited to 50 MB per file and 500,000 triangles after import. Individual operations may have lower limits described below. Performance depends on your device.

JavaScript, WebAssembly and WebGL are required for the interactive workspace.

How are models processed?

Mesh loading and rendering use Three.js. STEP import and tessellation use occt-import-js, based on Open Cascade. These sources describe the underlying libraries; this tool's supported features and limits are listed on this page.

Frequently asked questions

How do I resize an STL to an exact dimension?

Confirm the source and output units, then enter the target X dimension. The model scales uniformly, so Y and Z change by the same ratio. You can also enter a scale percentage. Check the displayed dimensions before exporting.

Can I scale X, Y and Z independently?

No. Scaling is uniform and preserves the model proportions. The target dimension control uses X; it does not provide separate non-uniform scale factors for all three axes.

Why is an inch-based model 25.4 times too small?

An OBJ or STL file contains coordinates without a reliable physical unit. If those coordinates represent inches but are interpreted as millimeters, the model appears too small. Choose Inches as the source unit and Millimeters as the output unit when that matches the source.

Do rotation and centering change the exported file?

Yes. The export uses the same transforms as the preview. Rotations are applied in X, Y and Z order, and centering moves the bounding-box center to the origin. Scaling and rotation do not perform mesh simplification.