Little Toolkit

Seamless Texture Seam Previewer

Inspect seams locally without modifying, repairing or exporting the source image.

Enable JavaScript for interactive processing. You can read the instructions, limits, and FAQs below without it. Files are processed only in your browser.

Seamless Texture Seam Previewer User Guide

Load one static PNG or JPG locally in the browser, then switch between the original, a gapless 3×3 tile, and horizontal or vertical half-size cyclic shifts to move joined edges where they are easy to inspect.

How to use

  1. Import one static PNG or JPG and verify its format, original dimensions, file size and estimated decoded memory.
  2. Switch among the original, 3×3 tile, horizontal left shift and vertical upward shift; odd dimensions use the half-size pixel value rounded down.
  3. Inspect pixel by pixel at 100% original size, switching between a checkerboard and solid background for transparent content; scaled view is only for an overview.

Formats and limits

  • One image at a time, up to 20 MiB / 12 million pixels (1,200 × 10,000), with each side up to 8,192 px and estimated RGBA decoded memory up to 48,000,000 bytes; only static PNG/JPG files are accepted.
  • The 3×3 tile reuses one source rather than creating nine huge canvases. Replacing or clearing the file, or leaving the page, invalidates the old result, but the browser is not guaranteed to reclaim all underlying memory immediately.
  • Fractional CSS scaling, device pixel ratio, browser decoding and GPU interpolation can create or hide false seams; only 100% view is suitable for pixel-by-pixel inspection.

Output

This is only a local on-screen preview. The tool does not modify the source, export shifted images, repair seams automatically or provide a seamlessness score.

Frequently asked questions

Does a visible seam always mean the source image has a problem?

Not necessarily. First switch to 100% original size and compare the tiled and cyclic-shift views; scaling interpolation, display ratio or browser decoding can all create visual false seams.

How many pixels are shifted for odd dimensions?

Horizontal shift uses floor(width / 2), and vertical shift uses floor(height / 2). The interface shows the exact integer shift; pixels only wrap cyclically, with no fill color or interpolation.

The file name and content are only processed in your browser and are not transmitted to the server. The original file will not be overwritten. Please export the required results before leaving the tool.