OneTaskBy Tim King · Updated
STL Thumbnail Generator
Render a PNG Preview of an STL, Free
OneTask is free, with no sign-up, and built by one person.
If this tool saved you time, a coffee helps keep new ones coming.
How the STL Thumbnail Generator works
This STL thumbnail generator renders a tidy square PNG of a 3D print file. Drop an .stl, choose a colour, an isometric, front or top view and a size of 256, 512 or 1024 pixels, pick a transparent or solid background and download the thumbnail. The model is framed and lit automatically, and it never leaves your browser.
STL thumbnail generator: one consistent picture per file
STL files have no built-in preview, so folders of print files show blank icons and shop or catalogue listings need a picture made by hand. A screenshot of a slicer works once but is hard to keep consistent across dozens of parts. This page renders every thumbnail the same way: the same camera angle, the same lighting, the model centred and filling the square, so a set of parts looks like a set.
What each setting does
- Colour sets the plastic colour. Orange and grey read well on white pages; white suits dark backgrounds.
- Thumbnail view sets the camera. Isometric looks down from the front corner and shows three sides, which suits most parts. Front is a straight elevation, and Top is a plan view, useful for flat parts such as badges and plates.
- Size sets the square PNG in pixels. 512 is plenty for listings; 1024 suits high-density screens and print.
- Thumbnail background can be transparent, so the image drops onto any page colour, or solid white, light grey or dark.
The viewport is only a preview: the downloaded PNG is rendered separately at the chosen size with its own camera, so you can orbit freely without changing the thumbnail.
Up axis
Printers build along Z, and nearly every STL is saved Z up, which the default respects. If the preview shows the part lying on its side, switch to Y up.
FAQ
Why is the thumbnail background checkered in my image viewer?
The background is transparent. Image viewers show transparency as a checkerboard; on a web page or in a document the page colour shows through. Choose White or Light grey for a solid background.
Can I make thumbnails for many files at once?
One file at a time. The settings stay as you set them, so drop the next file and download again to keep a consistent set.
Can it render a 3MF or OBJ file?
This page reads STL. Convert an OBJ with the OBJ to STL converter, or use the PNG button in the 3MF viewer for a screenshot of a 3MF.
See also: all 3D Model Viewers tools, Images, Audio, Video & Screen, PDF, SVG, Simulations & Screensavers, Generative Art, Chart Makers, Drawing Pads, Mockups & 3D Making, Diagram Makers, 3D Science, Tracker Music.
Related tools
STL Viewer
Drop an STL, orbit it, read its size and triangle count, save a PNG.
STL Dimensions Checker
Check an STL's size, volume, weight and whether it is watertight.
3MF Viewer
Open a 3MF print file, orbit it and check its parts and size.
STL To GLB
Convert STL to GLB in the browser with colour and up-axis fixed.
3D Print Cost Calculator
STL volume, filament weight and material cost from infill and price per kilo.