---
title: "Adjust Axis"
description: "Convert 3D models between Y-up and Z-up online. Keep STL, OBJ, or GLB, preview the ±90° X rotation, and download. Runs entirely in your browser, no upload."
toolId: "adjust-axis"
category: "editing"
subgroup: "model-transform"
subgroupName: "Model Transform"
url: "https://any3d.cc/en-US/tools/adjust-axis"
markdown: "https://any3d.cc/llm/tools/adjust-axis.md"
---

# Adjust Axis

Switch the up axis to match your software convention, preview the rotation, and export in the same format.

**Category:** 3D Model Editing Tools (`editing`)
**Subgroup:** Model Transform (`model-transform`)

**HTML:** https://any3d.cc/en-US/tools/adjust-axis

> Runs entirely in the browser. Files are not uploaded to Any3D servers.

## Overview

This tool converts a model's up axis between coordinate conventions: Y-up is common in glTF, Three.js, and web or game engines, while Z-up is the convention in Blender, CAD, and slicing software. The model is rotated ±90° around X, vertex coordinates are rewritten, and dimensions stay exactly the same. The download keeps the original format. Leave the source axis on Auto to follow the format convention (GLB and OBJ are Y-up, STL, 3MF, and STEP are Z-up), or set it manually when the file's real orientation differs.

## Tips

- Works with exportable mesh formats such as STL, OBJ, GLB, 3MF, and STEP.
- The viewport previews the exact export rotation: ±90° around X when source and target differ.
- All processing happens locally in your browser, and files are never uploaded.

## About Configuration Options

### General Settings

- **Transform Application** (Default: Modify root node): Choose how the transform is applied to the model: by modifying vertices (baked into geometry data) or by modifying the root node transform. Modifying vertices rewrites all vertex coordinates and applies consistently to every export format; modifying the root node keeps the original vertex coordinates, which is friendlier to animated, skinned, or geometry-sensitive workflows. Root node transform is the recommended default.
  - `bake` — Modify vertices: The transform is written into all vertex coordinates, rewriting geometry data; applies consistently to every export format.
  - `node` — Modify root node (Recommended): The transform is written to the root node (position/scale/rotation) while vertex coordinates stay unchanged; friendlier to animated or skinned models, but formats that ignore node transforms (such as STEP) won't apply it. Recommended default.

### Adjust Axis

- **Source up axis** (Default: Auto): The up axis the model currently uses. Auto follows the format convention (GLB and OBJ are usually Y-up; STL, 3MF, and STEP are usually Z-up). Set it manually when the file's actual orientation differs from the convention.
  - `auto` — Auto (Recommended): Use the format's declared up axis; treat undeclared formats as Y-up.
  - `y-up` — Y-up: Convention of OpenGL, Three.js, and most Web engines.
  - `z-up` — Z-up: Convention of Blender (default), 3ds Max, and most CAD and slicing software.
- **Target up axis** (Default: Y-up): The up axis the exported file will use. When it differs from the source, the model rotates ±90° around X with no size change.
  - `y-up` — Y-up: Best for web preview, glTF/GLB workflows, and Three.js.
  - `z-up` — Z-up: Best for Blender, CAD, and 3D printing slicers.

## Format Information

### Input / Output

- **Extension:** Model
- **Full Name:** 3D Model
- **Type:** 3D Model
- **Format:** Various 3D Formats
- **Tools:** [Three.js](https://threejs.org), [Babylon.js](https://www.babylonjs.com)
- **Open With:** Windows 3D Viewer, [Blender](https://www.blender.org)
- **Description:** Supports many 3D formats (GLB, GLTF, OBJ, FBX, STL, etc.). Drag and drop to view.
- **Supported Features:**
  - Real-time GPU-accelerated rendering via WebGL
  - Orbit controls: rotate, pan, zoom
  - Wireframe and shaded display modes
  - Model info panel with vertex/face counts
  - Animation playback for animated formats
- **Notes:**
  - Supports 20+ 3D model formats
  - Associate texture files (MTL, images) can be uploaded alongside the main model
  - All processing is local, so files never leave your browser

## How to use

### 1. Upload Model

Drag and drop or browse for your 3D file

### 2. Apply Transform

Use the sidebar panel to apply the desired operation

### 3. Preview

Rotate and inspect the result in the 3D viewer

### 4. Export

Choose output format and download the transformed model

## FAQ

### How is this different from the up axis toggle in the viewer?

The viewer toggle only changes how the model is displayed, so the downloaded file keeps its original coordinates. This tool writes the rotation into the exported file, which then opens with the target convention in other software. Use it before printing or handing off a model.

### How is this different from the Rotate 3D Model tool?

Rotate 3D Model applies any angle around any axis for manual posing. Adjust Axis performs the single ±90° X rotation that converts between Y-up and Z-up, so you do not have to work out the angle yourself.

### How is this different from the up axis option in the converter?

The math is identical, a ±90° rotation around X, but the converter also changes the file format, for example STL to GLB. Adjust Axis keeps the original format and only rewrites the coordinate convention.

### Which software uses Y-up, and which uses Z-up?

Y-up is standard in OpenGL, Three.js, glTF/GLB workflows, and most game engines. Z-up is the Blender default and is common in 3ds Max, CAD, and 3D printing slicers. This site treats STL, 3MF, and STEP as Z-up.

### I picked the target axis, but the model still lies on its side. Why?

The file's actual orientation probably differs from its format convention, for example an STL exported as Y-up. Set the source up axis from Auto to Y-up or Z-up and export again.

### Does changing the axis affect size, units, or precision?

No. Rotation preserves all distances, proportions, and precision, and no unit conversion is involved. To place the model on the print bed afterwards, run the Drop to Ground tool.

### Should I modify vertices or the root node?

Same tradeoff as the other transforms. Modifying vertices writes the rotation into every coordinate, so geometry-only formats such as STL and 3MF apply it. Modifying the root node keeps the original vertices, which suits animated or hierarchical models, but formats that ignore node transforms, such as STEP, will not follow.

### Is Any3D completely free?

Yes, Any3D's core features are free to use forever. We provide format conversion, model optimization, and online preview at no cost, with no registration required.

### Are my files uploaded to your servers?

No. Files you select are processed only in your browser on this device, so they never leave your device and are never sent to our servers. We don't store any user files; after processing, related data in browser memory is released.

### Do I need to install software?

No installation required. Any3D is entirely browser-based; just open the webpage to use all features. It works on Windows, Mac, Linux, and other major operating systems.

### Is there a file size limit?

The processing capacity depends on your device performance and the model's vertex count and texture complexity, rather than file size alone. We impose no file size limit, but when a model exceeds what your device can handle, the page may lag or even crash.