Free Image to STL Converter
Turn your PNG, JPG, logo, or photo into a 3D-printable STL file. Heightmap, extrude, and lithophane modes — all online, no install required.
Image to STL conversion transforms a 2D image (PNG, JPG, or JPEG) into a 3D mesh model saved in the STL (Standard Tessellation Language) file format. The resulting STL file can be sliced for 3D printing, loaded into CAD software like Blender, or used for CNC machining.
There are several ways to interpret a flat image as 3D geometry. The most common method is the heightmap approach: the tool analyzes the brightness (luminosity) of each pixel and maps it to a height — a white pixel becomes the tallest point, a black pixel the lowest. Other modes extrude a logo into a solid, or create lithophanes that reveal an image when backlit.
How to Convert an Image to STL
- 1
Upload your image
Select a PNG or JPG file. Most tools accept images up to a large resolution and will resize if needed for processing.
- 2
Choose your conversion mode
Pick heightmap, extrude, or lithophane mode, then adjust options like detail level, model height, smoothing, and invert output.
- 3
Download your STL file
Preview the generated 3D model, then download the STL file ready for your slicer or 3D editing software.
How Does Image to STL Conversion Work?
In Standard (heightmap) mode, the tool converts your image to greyscale and examines the brightness of each pixel. A black pixel maps to a height of 0mm and is excluded from the model, while a white pixel maps to the maximum height you specify. Pixels in between get a proportional height, producing a continuous relief surface.
In Extrude mode, the tool extrudes regions of the image into solid geometry, optionally overlaying color data (supported in color-capable formats like OBJ, 3MF, or GLB). For lithophanes, the model is printed thin enough that light shining through it reproduces the original image — dark pixels print thicker, light pixels thinner.
Image to STL Conversion Modes
| Mode | Description |
|---|---|
| Standard (Heightmap) | Pixel brightness determines height — ideal for grayscale terrain, photos, and relief sculptures. |
| Extrude | Extrudes image regions into solid 3D geometry. Great for logos, text, and badges. |
| Lithophane | Thin 3D-printable panel that reveals the image when backlit. Popular for lamps and light boxes. |
| Color Heightmap | Uses color channels to map height (e.g., dark blue = lowest, red = highest). Requires color-capable output formats. |
Why Use an Online Image to STL Converter?
🖥️ No Software to Install
Everything runs in your browser. You don't need a powerful computer or expensive 3D modeling software — conversion happens on dedicated servers or locally in the browser.
📱 Works on Every Device
Whether you're on Windows, macOS, Linux, Android, or iOS, the tool works the same. Convert images to STL from a laptop, tablet, or phone.
🔒 Safe & Private
Reputable converters do not store your uploaded image permanently. Files are typically deleted within hours of conversion, and download links expire automatically.
⚡ Fast Conversion
Most image to STL conversions complete in seconds. Processing time scales with image resolution and the selected detail level.
Common Use Cases
💡 Lithophane Lamps & Light Boxes
Convert family photos into backlit 3D-printed panels for lamps, night lights, and decorative light boxes.
🗿 Relief Sculptures & Art
Turn grayscale artwork or photos into 3D reliefs suitable for CNC carving or decorative 3D prints.
🏷️ Logos & Branding
Extrude company logos and text into solid 3D models for signs, keychains, and promotional items.
🗺️ Terrain & Topography
Convert elevation maps into 3D terrain models for dioramas, education, and geographic visualization.
What Is an STL File?
STL (Standard Tessellation Language) is the most widely used file format for 3D printing. It describes only the surface geometry of a 3D object as a mesh of triangular faces, without storing color, texture, or material information. STL files come in two variants: ASCII (human-readable but large) and Binary (compact, universally supported). Nearly every 3D printer, slicer, and CAD application supports STL, making it the default choice for sharing and printing 3D models.
STL vs Other 3D Formats
| Format | Color | File Size | Best For |
|---|---|---|---|
| STL | No | Compact (binary) | 3D printing, universal sharing |
| OBJ | Yes | Medium | 3D editing, rendering |
| 3MF | Yes | Small (compressed) | Modern 3D printers (Bambu, Prusa) |
| glTF | Yes | Small | Web display, AR/VR |
3D Printing Tips for Image to STL Models
- Use a layer height of 0.1–0.15mm for lithophanes to preserve fine detail.
- Print lithophanes in white PLA or PETG for the best light transmission.
- For heightmap reliefs, enable support material if the model has steep overhangs.
- Infill is irrelevant for solid lithophanes — set 15% to save material on large models.
Frequently Asked Questions
What does an image to STL converter do?
▾
It converts 2D image (bitmap) data into 3D geometry, then saves the result as an STL file. The geometry is typically generated from pixel brightness in heightmap mode, or by extruding image regions.
What image formats can I convert to STL?
▾
Most tools support common formats like PNG, JPG/JPEG, and BMP. PNG is recommended because it supports transparency and lossless quality, which produces cleaner 3D geometry.
What is a heightmap and how is it used for STL?
▾
A heightmap is an image where each pixel's brightness represents a height value. The converter reads pixel luminosity and builds a 3D surface where bright pixels are tall and dark pixels are short or flat.
What is a lithophane?
▾
A lithophane is a thin 3D-printed panel whose thickness varies with image brightness. When lit from behind, the varying thickness lets light through differently, reproducing the image. Dark areas print thicker; light areas print thinner.
Is my image safe when I upload it?
▾
Reputable online converters do not store your image permanently. The converted STL and your upload are typically deleted within a few hours, and the download link expires automatically after that period.
How long does image to STL conversion take?
▾
Most conversions finish in around 5 seconds, though larger images or higher detail settings can take longer. Processing happens on dedicated servers, so your computer's specs don't matter.
Do I need a powerful computer to convert images to STL?
▾
No. Conversion runs on the server (or in your browser for client-side tools), so you can use low-spec laptops, tablets, and even phones and still get your STL quickly.
Does STL support color?
▾
Standard binary STL only stores geometry — no color, texture, or material data. If you need color (e.g., from an extrude-color conversion), use a color-capable format like OBJ, 3MF, GLB, or DAE instead.
What image resolution works best for STL conversion?
▾
For heightmap and lithophane modes, use images between 500 and 2000 pixels on the longest edge. Higher resolution captures more detail but increases file size and processing time. Very large images are automatically downsampled to a manageable resolution.
Can I convert a color image to STL?
▾
The STL file format does not support color. If your source image is color, it is converted to grayscale first, and the brightness determines the height. For color 3D models, export to OBJ, 3MF, or GLB instead.
What is the difference between heightmap and extrude mode?
▾
Heightmap mode creates a smooth relief where pixel brightness maps to a continuous height range. Extrude mode thresholds the image and lifts bright regions to a fixed height, producing a solid block shape ideal for logos and text.
Do I need to invert my image before converting to a lithophane?
▾
No. Lithophane mode automatically handles the inversion — dark pixels print thicker (blocking more light) and light pixels print thinner. Just upload your original photo and select the lithophane mode.
Related Tools
3MF to STL Converter
Convert 3MF files to STL format entirely in your browser, with a live 3D preview before downloading.
STL Viewer
Open and preview STL files instantly in your browser with zoom, rotate, and pan — no install needed.
AI 3D Model Generator
Turn any image into a production-ready 3D model in seconds using AI. Export as STL, OBJ, or GLB.