Click the preview to fill your screen with the repeat. Look along the tile edges: a seamless pattern shows no lines or breaks where tiles meet; if you can trace the grid, the pattern is not seamless yet.
See Seams Before Your Printer Does
A seam that is invisible in a single tile becomes an obvious line once the pattern repeats across a metre of fabric. Tiling your design first turns a costly misprint into a five-second check.
Check Any Pattern, From Any Source
It does not matter where your tile came from — an AI generator, Photoshop, a scanned texture, or a stock marketplace. If it is a JPG or PNG, you can drop it in and see exactly how it repeats.
Your Images Never Leave Your Browser
The whole check runs locally on your device. Nothing is uploaded, nothing is stored, and no account is needed — so you can check unreleased or client work without it ever touching a server.
Skip the Fixing — Generate Seamless Patterns
Repairing a tile's edges by hand is slow and fiddly. Patternful AI generates patterns that are seamless by construction, so they tile perfectly in every direction and pass this check by default.
Frequently Asked Questions
What does it mean for a pattern to be seamless?
A seamless pattern is a single tile whose edges line up with themselves when repeated. The right edge continues into the left edge, and the bottom continues into the top, so the tile can be repeated endlessly across fabric, wallpaper, or a web background with no visible joins.
How does the seamless checker work?
Upload a pattern tile and the checker repeats it in a grid, exactly the way a printer or a CSS background would. Repeating the tile is what makes seams obvious: any mismatch at the edges turns into a hard line running through the grid, which is difficult to spot when you are only looking at a single tile.
How do I read the result?
Look along the boundaries where tiles meet. If the pattern flows across them and you cannot tell where one tile ends and the next begins, your pattern is seamless. If you can trace the grid — visible lines, abrupt colour or texture shifts, motifs cut in half — the tile is not seamless yet.
Why does my pattern show seams?
The most common causes are motifs that run off one edge without continuing on the opposite edge, a background gradient or vignette that is lighter on one side, and cropping or resizing a tile after it was made, which shifts the edges out of alignment. Photographed textures also rarely tile, because their lighting falls off toward the edges.
What image formats can I check?
JPG and PNG files up to 8MB. Square tiles give the most representative preview, since that is how seamless patterns are normally produced and printed.
Is the checker free, and are my images private?
The checker is completely free, with no account and no credits. Your image is never uploaded: the whole check runs in your browser, so the file stays on your device and nothing is sent to our servers.
My pattern is not seamless — how do I fix it?
You can retouch the edges by hand, or skip the problem entirely and generate a pattern that is seamless by construction. The Patternful AI seamless pattern generator produces tiles that repeat perfectly in every direction, so they pass this check by default.