Seamless Texture Checker
Test whether an image tiles without visible seams. The checker repeats your image in a 2×2 grid, measures how well opposite edges match, and highlights exactly where a seam would show.
🔒 Your image is processed entirely in your browser. Nothing is uploaded to any server.
2. Seam Report
Upload an image above to see how it tiles
3. Tiled Preview (2×2)
Upload an image above to see how it tiles
How It Works
The checker compares the image's opposite edges pixel by pixel — the right edge against the left, the bottom against the top — because that is exactly what meets when the image repeats. Each boundary step is then measured against the image's own neighbouring-pixel differences beside the edge, so smooth gradients don't count as seams: the score reports only the excess jump at the boundary. 0% means the wrap looks like any other pixel transition; higher numbers mean an increasingly obvious seam.
The 2×2 preview shows the actual repeat, and the seam highlighter paints the boundary pixels whose mismatch exceeds the visibility threshold. Textures from the Texturize generators score 0% by construction; photographs almost always need a blending pass first.
Seamless Checker — FAQ
What does the edge-mismatch score mean?
It measures how much larger the jump across the repeat boundary is than the image's normal pixel-to-pixel variation, averaged along both edges and expressed as a percentage of the full colour range. That baseline matters: opposite edges of a perfectly seamless gradient still differ slightly, like any two neighbouring pixels do. Under about 1% the repeat is effectively invisible; above roughly 4% most people will spot the seam at a glance.
Can a texture score well and still look repetitive?
Yes. The score only measures edge continuity. A distinctive stain or highlight inside the tile will still read as a repeating motif even with perfect edges. Check the 2×2 preview: if your eye finds the same feature four times, crop or retouch the source, then re-check.
My image fails — how do I fix it?
Use the Make Seamless tool: Blend mode cross-fades the offset edges and suits organic surfaces, while Mirror mode guarantees a perfect repeat on any input. Re-run the result through this checker — a blended image should land near 0%.
Is the checker free, and is my image uploaded?
Free, no account, no watermark. The comparison runs in your browser with the Canvas API, so the image never leaves your device.