How to convert image to STL
How to convert an image to STL for 3D printing
How to convert an image to STL is not one workflow — it is three. Heightmaps make reliefs. Extrude tools thicken logos. Single-image AI builds a mesh object draft. This guide covers the decisions, then the PhotoSTL path for makers who need STL/3MF in millimeters. 30 free credits (≈3 drafts) when you sign in (Google or magic link).
1. Choose the method that matches the print
- Heightmap / lithophane — flat panel, brightness = thickness. Use a dedicated relief tool.
- Silhouette extrude — logo or line art with constant depth. Use a vector/extrude converter.
- AI full 3D — one photo of a real subject → mesh you can rotate. That is what PhotoSTL does. See AI vs heightmap.
2. Prepare the source image
Crop tightly to one subject. Prefer a plain background and even lighting. For logos, high contrast beats soft gradients. For photos, avoid heavy compression artifacts if you can re-export from a cleaner master (see JPG to STL and PNG to STL).
3. Convert with a print recipe on PhotoSTL
- Open photostl.com and sign in for 30 free credits (≈3 drafts).
- Pick a recipe: general object, pet bust, logo relief, miniature, jewelry, product, or architecture.
- Upload JPG / PNG / WebP and generate — typically about 30 seconds.
- Set target height in mm, then download STL or 3MF.
4. Inspect the mesh in your slicer
Confirm the bounding box in millimeters, look for thin limbs or open edges, and add supports where needed. Draft readiness tips on PhotoSTL are advisory — they never block download.
Failures that account for most bad prints
- Wrong method (heightmap when you wanted a free-standing object).
- Busy background competing with the subject.
- Skipping the slicer check and printing a draft as-is.
- Tiny features smaller than two extrusion widths after scaling.
FAQ
How do I convert an image to STL online?
Decide the method first (heightmap, silhouette extrude, or AI full 3D). For a printable object draft from one photo, open photostl.com, sign in for free credits, pick a print recipe, upload JPG/PNG/WebP, generate, then download STL or 3MF in millimeters.
Why does my image to STL look flat?
Most free converters map brightness to height. That produces a relief panel, not a reconstructed object. If you need a bust, miniature, or product prop, use a single-image AI image to 3D tool instead of a heightmap.
What image works best before conversion?
One centered subject, plain background, even lighting, and enough resolution that edges are clear. Busy scenes, heavy JPEG noise, and tiny disconnected parts make worse meshes.
Do I still need a slicer after converting?
Yes. STL/3MF from PhotoSTL is a print draft. Open it in Cura, PrusaSlicer, Bambu Studio, or similar — set walls, supports, and layer height before you print.