SEAMLESS PATTERN TESTER
Finding pattern seams
The centered seam view wraps the source tile by half its width and height. The original left/right and top/bottom joins move into the center, making abrupt changes easier to inspect. This view does not apply the selected repeat mode or repair the image.
How it works
Edge difference compares sampled opposite-edge RGB values after compositing transparency on white. Values range from 0% (matching sampled pixels) to 100% (maximum difference). Low values do not detect all visual problems; inspect lines, shapes and tonal changes in the repeat preview too.
Test a pattern ↗Repeat modes explained
A straight repeat places identical copies in aligned rows and columns. Half-drop shifts alternate columns vertically by half a tile. Brick shifts alternate rows horizontally by half a tile. Mirrored repeat flips alternate tiles horizontally and vertically.
↗02Finding pattern seams
The centered seam view wraps the source tile by half its width and height. The original left/right and top/bottom joins move into the center, making abrupt changes easier to inspect. This view does not apply the selected repeat mode or repair the image.
↗03Exporting pattern PNGs
Repeat exports are PNG files from 256 to 4096 pixels on each side. They keep the preview’s horizontal pattern coverage; changing the export aspect ratio reveals more or less vertical area. Guides and the checkerboard are never included. Transparent background preserves transparency.
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