Image Stitcher and Collage

Features

• Three layouts: tall strip, side by side, and grid
• Grid columns can be set, or derived from the image count
• Gap from 0 to 64 pixels — 0 gives a seamless tall image
• Uniform sizing uses the narrowest image and never upscales
• Per-image rounded corners, on transparent, white, black or off-white
• Output as PNG, WebP or JPEG; a transparent background becomes white for JPEG and says so
• A canvas past the browser limit is reported up front instead of returning a blank image
• Drop files, pick several at once, or paste screenshots — nothing is uploaded

How to use

1. Drop several images in at once (or click to choose and select multiple)
2. Pick the layout: Vertical for a tall image, Horizontal to compare, Grid for tiles
3. Set the gap to 0 for a seamless strip; keep uniform sizing when sizes differ
4. Download the result, or right-click the preview to save it

FAQ

Why is the tall image taller than I expected?

Almost always the gap. The default suits collage-style output; for stitching screenshots set it to 0 so there is no empty space between images and the pixels of one tile sit directly against the next. Also note that uniform sizing rescales each image proportionally, so a narrower width also means a shorter height and the total can differ slightly from what you worked out by hand.

My images have different widths — will uniform sizing enlarge the small one?

No. The target is the narrowest of the set, so only the larger ones shrink and the small one stays as it is. Doing it the other way round (scaling up to the widest) turns a small image into a mosaic, which is the usual disappointment with stitching tools. If you do need to enlarge one, run it through the format converter first and stitch the enlarged version.

How many images can I combine at once?

It depends on size rather than count. Browsers cap a canvas at 16384 pixels per side and roughly 64 million pixels in total, and past that it fails — so ten 4K screenshots stacked vertically will not fit, while twenty phone screenshots usually will. The tool works this out before processing, tells you which limit was hit, and suggests uniform sizing or a smaller gap.

Are the images uploaded?

No. Stitching uses the browser's own canvas entirely in local memory — the images never leave the machine, and it keeps working offline. That matters especially for screenshots, which tend to carry chat logs, order numbers or client names.