Image to STL Converter
Turn a PNG or JPG into a 3D-printable STL in your browser. Brightness becomes height, giving a relief with a flat back. Free, and nothing is uploaded.
Runs in your browser. Your files never leave your device.
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Free, no sign-up. Built on the Canvas API and a mesh builder written for UpAgents (no extra library). Updated 2026-10-22.
What does an image to STL converter do?
An image to STL converter reads how bright each pixel is, turns that into height and closes the shape into a solid you can print. Bright areas stand up and dark areas stay low, or the other way round. The result is a relief with a flat back, like an embossed picture, not a full 3D model.
How to convert an image to STL
- 1Drop a PNG, JPG or WebP on the box above, or click the box to choose it.
- 2Set the width, the base and the top height in millimetres.
- 3Tick Dark areas stand up if your logo is dark on a light background.
- 4Check the shaded preview, click Download STL and open the file in your slicer.
Image to STL or image to 3D model: which do you need?
Use image to STL for logos, signs, outlines, embossed photos, plaques and keychains: anything you look at from the front. For a figure you can walk around, like your dog, you need an image-to-3D model that builds the hidden sides, then a repaired and sized mesh. That is the job of the 3D Print File Agent.
What size and thickness should a relief be?
For a plaque or sign, 100 to 150 mm wide with a 1.5 to 2 mm base and 3 to 5 mm of relief reads well on an FDM printer. Keep the height steps between areas above your layer height (0.2 mm on most printers) and use a high-contrast image: soft gradients become gentle slopes that are hard to see.
Guides for this job
- 3MF vs STL: Which File to Use for Multicolour 3D Prints
STL stores only shape; 3MF adds units, colours, parts and print settings. When to use each, how to print a photo in multicolour, and how to convert.
- How to Check and Repair an STL Before You Print
What a watertight (manifold) STL is, the five mesh errors that stop a print, how to check and repair an STL for free, and why watertight isn't printable yet.
- How to Turn a Photo into a 3D Print File: Lithophane, Relief or Full Model
Turn a photo into a 3D print file three ways: a backlit lithophane, a relief plaque, or a full 3D model of your pet. Which to pick, the settings and free tools.
Questions
Is this image to STL converter free?
Yes, with no sign-up and no watermark. The conversion runs in your browser, so there's no upload and no queue.
Can I convert a PNG or JPG to STL?
Yes. PNG, JPG and WebP all work, as does any other image your browser can open. Transparent areas count as white.
Will it make a 3D model of my dog or a person?
No. It makes a relief from brightness, like an embossed picture. A full 3D model needs an AI that builds the hidden sides; the 3D Print File Agent does that and checks the result for printing.
Is the STL watertight?
Yes. The mesh is closed by construction: a top surface, four walls and a flat bottom, with every edge shared by exactly two triangles. Slicers open it without repairs.
Why is my STL file so big?
STL stores every triangle, so fine detail on a large piece can pass 20 MB. Choose Standard or Draft detail for a smaller file. At 0.3 mm the grid is already finer than a 0.4 mm nozzle can print.
Is my image uploaded?
No. Your browser reads the image and builds the STL on your device. Nothing is sent to UpAgents or anywhere else.