Perler Bead Pattern Maker (Hama, Lego Mosaic)

When a child brings a picture of a favorite character and asks for it in beads, this tool turns the picture into a grid pattern for fuse beads (Perler-like and Hama-like ranges), brick mosaics or cross-stitch. Each cell gets the nearest real color and a number, and the page shows how many beads of each color you need, how many boards, and the finished size in centimeters. The first printed sheet shows the whole picture and the key; each following sheet is one board with numbered cells, ready to hand over.

How to use

1. A pattern made from the cat-face sample is shown first. To use your own picture, click "Drop a photo or drawing here or click to choose", or paste a screenshot with Ctrl+V.
2. Under "Color chart", choose the range that matches your materials. To use fewer colors, turn on "Use fewer colors (keep the common ones)" and set "Most colors".
3. Under "Set the size by", "Boards" fits the picture to 1, 2 or 4 boards of 29 × 29; "Beads across" lets you type the width. For bricks, pick a 32 × 32 or 16 × 16 plate under "Board type".
4. To leave the background empty, choose "Leave empty (edge color, automatic)" or "Leave white empty" under "Background" and adjust "How close to the background". If the result looks blurry, turn on "Sharp edges (each cell takes its main color)" or move "Brightness" and "Contrast".
5. Tap a color in the key to show only its cells while you place beads. Use "Save as PDF", "Print" or "Save PNG"; for a black-and-white printer set "Board pages" to "Black-and-white numbers only".

How it works

• Colors are compared in the CIELAB color space with the CIEDE2000 color-difference formula, which follows how the eye judges similar colors better than subtracting RGB values.
• The chart colors and names are approximations chosen for this tool, not manufacturer color numbers. The codes F01, H01, L01 and S01 are positions in this tool's own lists. Perler, Hama, Lego and DMC are trademarks of their owners.
• Finished sizes use a spacing of 5 mm for beads, 8 mm for bricks and 25.4 ÷ 14 ≈ 1.81 mm for 14-count Aida. Ironed beads may shrink a little.
• Pictures are processed in this browser on this device and are never uploaded. Only your settings are saved in this browser.

How a photo becomes a bead pattern

The picture is divided into a grid and each cell takes the average color of the pixels inside it. Transparent pixels are left out of the average, and a cell that is more than half empty stays empty. With "Sharp edges" turned on, a cell takes the color that covers most of it instead of the average, so outlines do not blend into their neighbors.

Next, each cell's color is replaced by the nearest color in the chosen chart. With "Use fewer colors" turned on, k-means clustering first groups the picture's colors into as many groups as "Most colors" allows, each group takes its nearest chart color, and only those colors are used. Dithering uses the Floyd–Steinberg method: the leftover color difference of each cell is passed on to its neighbors, so dots of two colors mix into an in-between shade.

Fixing a bead pattern that looks wrong

A face or character that turns into a blur usually has too few cells. One board (29 cells across) shows little more than eyes and a nose, so try 2 or 4 boards or set "Beads across" to 40 or more. For a photo with a lot of background, "Fill (crops edges)" makes the main subject larger.

If there are more colors than you have beads for, lower "Most colors" to about 8 to 12. If smooth areas such as skin or sky get speckled, turn dithering off; turn it on only when you want to keep the gradients of a photo. If removing the background also removes part of the subject, lower "How close to the background".

Printing and placing a pattern of several boards

The first printed sheet shows the whole picture, the total number of beads and the color key, with board edges drawn as red lines. Each following sheet covers one board with a color number in every cell. Its heading says which columns and rows of the whole pattern it shows, and the key below lists how many beads of each color that board needs.

When you use several boards, join them first and fill them in sheet order. Count along the thicker line drawn every 10 cells to keep your place. Iron all boards at once at the end so the joins between boards stay neat. On a black-and-white print, find each color by its number in the key.

Questions and answers

How many pegs are on a Perler bead board?

The common large square pegboard has 29 × 29 pegs, 841 in all. "Boards" in this tool uses that size for 1 board, 2 side by side, 2 one above the other, or 4 boards (58 × 58).

How do I work out the finished size of a bead pattern?

Multiply the number of cells by the bead spacing. With 5 mm beads, 29 cells give 29 × 5 mm = 14.5 cm; with 8 mm bricks, 23.2 cm.

Are the color numbers the same as the bead maker's numbers?

No. The colors and names are approximations, and the numbers are positions in this tool's list. When you buy beads, compare the swatch and name in the key with the real colors.

Can I make a Lego mosaic pattern?

Yes. Choose "Bricks, 32 basic colors (Lego-like)" under "Color chart"; "Board type" changes to the 32 × 32 baseplate and the finished size uses 8 mm spacing.

Can I use it as a cross-stitch pattern?

Choose "Cross-stitch floss, 60 colors (DMC-like)"; the finished size on 14-count Aida is shown as well. The numbered grid works as a cross-stitch chart.

Is my photo uploaded to a server?

No. The picture is processed inside the browser and is not sent anywhere.