STL to PNG Converter

Turn an STL file into a PNG picture right in your browser. Pick a view (front, back, left, right, top, bottom or isometric, or turn the model by hand), a size up to 4096 × 4096 pixels and a transparent, white or coloured background, and download the PNG. The model is drawn by your graphics card with a depth buffer, so the nearest surface is always the one you see, even in complex parts. Choose orthographic (true proportions, as in a technical drawing) or perspective, smooth or flat shading, a colour, and sharp edges drawn as lines. Tick several views to get them all in one ZIP, or as one contact sheet; add several STL files and the ZIP has every view of every file. Nothing is uploaded.

100% private — everything runs in your browser. Everything runs in your browser; your STL files are never uploaded.

How to convert an STL to PNG

1. Drop one or more STL files on the box, or click Try a sample.
2. Choose the view, size, background and shading; the picture below the 3D view shows the PNG as it will be saved.
3. Click Download PNG.
4. For a set of pictures, tick the views you want and click Ticked views (.zip) or Contact sheet (.png).

What you can use it for

• Make product or listing pictures of a 3D print with a transparent background
• Add front, top and side views of a part to a document or quote
• Make thumbnails for a whole folder of STL files in one go
• Show a model on a website or in a chat without a 3D viewer
• Make an isometric picture for instructions or a parts list
• Check which way faces point with the normal-colour shading

The views

View	Camera looks from	Right in the picture	Up in the picture
Front	−Y	+X	+Z
Back	+Y	−X	+Z
Left	−X	−Y	+Z
Right	+X	+Y	+Z
Top	+Z	+X	+Y
Bottom	−Z	+X	−Y
Isometric	(0.5774, −0.5774, 0.5774)	(0.7071, 0.7071, 0)	(−0.4082, 0.4082, 0.8165)

STL files have Z up, as on a 3D printer’s bed, so the front view looks along +Y with Z up. Isometric looks from the front right top, at equal angles to all three axes. Computed by the page’s own view code.

How big the model is in the picture

PNG size	Pixels	Our 60 × 40 × 46 mm L bracket, front view	Same bracket, isometric view
512 × 512	0.26 MP	451 × 345 px	406 × 451 px
1024 × 1024	1.05 MP	901 × 691 px	813 × 901 px
2048 × 2048	4.19 MP	1802 × 1382 px	1626 × 1802 px
4096 × 4096	16.78 MP	3604 × 2763 px	3252 × 3604 px
1920 × 1080	2.07 MP	1240 × 950 px	857 × 950 px

With the default margin of 6 % on each side, the model is scaled to fill the picture; change the margin from 0 to 40 %. Computed by the page’s own framing code.

Picture settings

Setting	Choices
Projection	Orthographic (true proportions) or perspective
Size	512 to 4096 px a side, square, 16:9, 4:3, 4:5 or any width and height
Background	Transparent (alpha channel), white or any colour
Shading	Smooth, flat (facets show) or normal colours (shows which way faces point)
Lines	Sharp edges (over 30°) drawn as dark lines
Several pictures	Ticked views of every file as one ZIP, or the ticked views of one file as one contact sheet PNG

What our test files give

Test file	What it checks	Triangles	Type	Size
l-bracket.stl	L bracket, binary	24	Binary	60 × 40 × 46
plate-hides-cube.stl	A plate in front of a cube (the cube must be hidden in the front view)	24	Binary	40 × 40 × 40
bar-inside-out.stl	A bar with every face turned inwards	12	Binary	120 × 10 × 10
open-sheet.stl	One open sheet	2	Binary	50 × 30 × 0
padded-binary.stl	Binary with 37 extra bytes at the end	12	Binary	20 × 20 × 20
bar-ascii.stl	ASCII STL	12	ASCII	30 × 10 × 5
sphere-16k.stl	A sphere with 16,128 triangles	16,128	Binary	50 × 50 × 50
bar-yup.stl	A bar exported Y-up	12	Binary	10 × 40 × 10

Our own STL test files. Each picture made from them was checked pixel by pixel against our own depth-buffer drawing of the same triangles: the nearest face wins, the background stays transparent and the PNG has the size asked for.

Next steps

Measure and check the model in the STL viewer, or make a dimensioned line drawing with Orthographic Drawing. Need a 3MF for a colour printer? Try STL to 3MF, or go back with 3MF to STL.

Sources

Sources: Library of Congress: STL (STereoLithography) File Format Family (triangles with a normal each, no standard colour); W3C: Portable Network Graphics (PNG) Specification (lossless, with an alpha channel for transparency).

Frequently asked questions

Is this STL to PNG converter free?

Yes. There is no sign-up, no watermark and no limit on how many pictures you make. Everything runs in your browser, so your STL files never leave your device.

Can the background be transparent?

Yes, and it is by default: the PNG keeps an alpha channel, so only the model is drawn. You can also choose white or any colour.

How large can the PNG be?

Up to 4096 × 4096 pixels, in any shape (square, 16:9, 4:3, portrait or a custom width and height). Some phones and older graphics cards allow less; the page tells you the largest size your browser can draw.

Which views can I make?

Front, back, left, right, top, bottom and isometric, as STL files are laid out (Z up, as on a print bed), plus the view you turned the model to in the 3D view. Tick several to get them in one ZIP or one contact sheet.

Orthographic or perspective?

Orthographic draws parallel lines as parallel and keeps every part at true scale, as in a technical drawing; it is the default. Perspective looks the way a camera sees the model, with far parts smaller.

Can I convert several STL files at once?

Yes. Add them together and Ticked views (.zip) makes every ticked view of every file, named after the file and the view.

Why is my model lying down?

Most STL files are Z-up, and the views follow that. If your file came from an app that writes Y-up, set Up axis in the STL to Y up.

Does it keep the colours of my model?

STL files have no standard colour, so the model is drawn in the colour you pick. Normal colours shading paints each face by the way it points, which shows faces that are turned the wrong way.

Is this a heightmap for CNC carving?

No. This makes pictures of the model as it looks. A grey heightmap for carving is a different kind of image.

Are my STL files uploaded?

No. The STL files are read and drawn by JavaScript and your graphics card in your browser, so they never leave your device. Only the 3D engine itself (three.js) is loaded from a public CDN. There is no sign-up and no watermark.