Closed-mesh check
Slicers print solids, not surfaces. The check counts open and non-manifold edges so you know whether the shell is watertight before you slice — not after a failed print.
3D printing workflow
Image to STL Converter for 3D Printing
Turn a photo into a 3D model, then prepare it for your slicer on the same page: check whether the mesh is closed, set the print size in millimeters, and export a binary STL. The mesh check and export are free and run in your browser.
2 steps
Generate, then prep
0 credits
Mesh check and STL export
100 mm
Default print height
Binary STL
Slicer-ready output
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Step 2 — print prep
Check the mesh and export the STL
A generated model is not automatically a printable one. Print prep verifies the shell, applies a real-world size, and writes the STL your slicer expects. Models you generate above arrive here automatically when you use the “Prepare for 3D printing” button.
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What the mesh check tells you
True size in millimeters
AI models are generated in arbitrary units. Set the height you actually want and the STL is exported at that real-world size, centered and seated flat on Z = 0.
Honest counts, no fake fixes
If the mesh has gaps, you see the exact numbers. Small gaps are normal for AI meshes and modern slicers repair them on import — we tell you that instead of pretending to rebuild the topology.
How it works
Step 1
Generate from an image
Upload a photo and the AI builds a 3D model you can preview in the browser. Generation uses the same credit system as the rest of Fastin3D; sample runs are free.
Step 2
Check and size the mesh
Print prep loads the model, counts open and non-manifold edges, and reports whether the shell is closed. Then set the print height in millimeters.
Step 3
Export the STL
Download a binary STL at true millimeter scale, ready to drop into Bambu Studio, OrcaSlicer, PrusaSlicer, or Cura.
Image to STL questions
How do I turn an image into an STL file?
It takes two steps on this page. First, generate a 3D model from your image with the generator above. Second, open the result in print prep: run the mesh check, set the print height in millimeters, and download the STL. The button on the generation result takes you straight there.
Is the exported STL ready to print?
The STL is written at true millimeter scale, centered on the build plate, and seated on Z = 0. If the mesh check reports a closed mesh, you can slice it directly. If it lists open edges, import the file into your slicer and let its repair step close the gaps — Bambu Studio, OrcaSlicer, PrusaSlicer, and Cura all do this automatically. No AI generator can promise a flawless mesh, which is why this page shows you the real edge counts instead of a fake “fixed” badge.
What does the mesh check actually measure?
It counts the triangles in the mesh, then checks every edge. An edge used by exactly one triangle is an open (boundary) edge — a hole in the shell. An edge shared by three or more triangles is non-manifold. A mesh with zero of both is closed, which is what slicers call watertight. Degenerate (zero-area) triangles are counted separately.
What size will my printed model be?
You choose the height in millimeters — 100 mm by default. Width and depth scale proportionally, and the exact export size is shown before you download, so there are no surprises in the slicer.
Does print prep cost credits?
No. The mesh check, sizing, and STL export run entirely in your browser and are free. Only the AI generation step uses credits, and the sample models on this page run free.
Which printers and slicers work with the exported STL?
The export is a standard binary STL, the default input for FDM and resin slicers including Bambu Studio, OrcaSlicer, PrusaSlicer, UltiMaker Cura, and Lychee Slicer.