Stained glass generator: turn your photos into a digital glass mosaic

There's something magical about a stained glass window – the way light breaks into hundreds of coloured facets, each separated by a dark lead line. Now imagine taking any photo and seeing it reimagined in that exact style. That's what a stained glass generator does. It applies a geometric grid (often a Voronoi diagram) to your image, fills each polygon with the average colour of the area, and draws bold black strokes along the edges – exactly like a vitrail artista would piece together coloured glass.

You don't need a single artistic skill to use it. I've been testing the Suite Créative tool (called Vitrail Mosaïque) and it's the smoothest one I've come across that runs completely inside your browser. Nothing leaves your machine, which is rare for image generators these days.

How the generator builds a stained glass effect

At its heart, the tool does three things very quickly:

• Creates a mesh of random points. The more points, the smaller the glass “pieces” will be. This is the cell count slider you see in the interface.
• Assigns ownership of each pixel. For every pixel in your photo, the algorithm asks: which of those points is closest? The answer defines the polygon cell that pixel belongs to. This is a Voronoi partition.
• Fills each cell with its average colour. Once the boundaries are defined, the tool averages all the colours inside that cell and paints it a single flat tint. Then it draws a black (or custom-colour) outline along the cell borders.

What you end up with is a crisp, faceted version of your original photo. The effect can be subtle (many cells, thin lines) or bold (fewer cells, thick black joints) depending on the mood you want.

Key settings that shape the final artwork

The Suite Créative stained glass generator gives you four intuitive controls:

• Cell count (number of polygons). With 150 cells, your photo becomes an abstract mosaic. At 600 or 800, the shapes become so small that the image stays highly recognisable while still retaining its geometric nature.
• Line thickness. In true stained glass, the lead joints are quite thick. You can mimic that by setting the outline to 3‑4 pixels, or go for a delicate wire‑frame look with 1‑2 pixels.
• Show joints. If you prefer a smooth, low‑poly effect without the black lines, simply toggle them off. The result resembles a modern geometric poster.
• White background. When checked, the area outside your subject stays white, keeping the focus on the main object. Uncheck it to let the polygon pattern fill the entire frame.

Adjusting these settings is immediate – the preview updates on the spot, so you can play until the image feels right.

What to create with a stained glass photo

The polygon aesthetic appeals to a wide range of projects:

• Wall art. Print the high‑resolution PNG on matte paper and frame it. The geometric style looks particularly striking as a series of portraits or animal studies.
• Custom gifts. Generate a stained glass version of a couple's portrait for a wedding or anniversary. It feels entirely handmade yet costs nothing to produce.
• Digital stickers and badges. The flat colour areas and clean outlines make it easy to turn the output into a sticker (using our sticker maker) or a social media badge.
• Embroidery patterns. Because each cell is a single colour, the design translates directly to cross‑stitch or mosaic crafts.
• Teaching material. Art teachers use the tool to demonstrate concepts of colour averaging, tessellation, and the difference between realistic and abstract representation.

The best part is that every image is processed locally. I've used this tool with client artwork and family photos alike, knowing that the files never travel beyond my own computer. That level of privacy is surprisingly rare among visual editors.

What makes a good stained glass photo

Photos with strong contrast and clear subject separation give the most dramatic results. A bright bird against a dark forest, a pale face against a deep red curtain – these high‑contrast edges guide the algorithm to create well‑defined polygon boundaries. Images with very subtle tonal variations (like a foggy landscape) still work, but the cells will be less distinct.

If you're unsure where to start, try a close‑up portrait of a pet. The texture of fur, the gleam in the eye, and the shape of the ears all interact beautifully with the polygon mesh. And because the tool doesn't require any login, you can experiment freely without any pressure.

Whether you're a designer looking for a fresh effect or just someone who wants to see their cat turned into a cathedral‑worthy masterpiece, the stained glass generator delivers. I've found myself returning to it more often than I expected – sometimes just to see what happens when I crank the cells up to 700.

Ready to give it a go? Open the tool, drop in a photo, and move the sliders. You might be surprised by what you create.

Related reading: The polygon mosaic: when photos meet geometry · Asian‑style portrait generator · Turn the result into a sticker