Join two or more pictures side by side, stacked, or in a grid. Set the gap, the background and a border, choose how mismatched sizes are handled, and download one file.
Lays your pictures out on one canvas in the order of the list, then draws them at full resolution into a single image. Side by side gives a row, Stacked a column, Grid a table with the number of columns you choose. Images of different sizes are the usual problem, so you decide how to reconcile them: keep every image at its own size, or make every cell match the largest, smallest or first picture, and then whether an odd-shaped image is fitted inside its cell, fills it and gets cropped, or is stretched. The result updates as you reorder, so you can see the effect before downloading.
A before-and-after pair: two 1600 × 1200 photos, Side by side, gap 24 px, white background, no border. The result is 3224 × 1200 and, as JPEG at quality 92, about 900 KB. Three phone screenshots of different heights for a bug report: Stacked, sizing Largest, Fit, gap 16 and a 2 px grey border gives a tidy 1170 × 7660 column. Six product shots as a contact sheet: Grid with 3 columns, sizing Smallest, Fill, gap 12, and every cell is the same size with the edges cropped rather than letterboxed.
Use it for comparisons, screenshot stitching, contact sheets, evidence for a report or a simple two-up for a shop listing. If you want freeform placement, overlapping pictures or one image on top of another, that is Overlay Image. For a designed layout with templates and rounded frames, Image Collage Maker is the better fit. If the pictures are huge, resize them first with Resize Image; a row of five 12-megapixel photos is a 60-megapixel file that some apps refuse to open.
Sizing Keep places each picture at its natural pixel size and centres it in the row or column; Largest, Smallest and First make every cell the same size. Inside the cell only matters when cells are uniform: Fit shows the whole picture with background around it, Fill crops the edges, Stretch distorts. Gap is the space between cells, in pixels of the final image. Border draws a frame around each picture in its own colour. The output is PNG by default so nothing is lost; switch to JPEG or WebP for a smaller file.
How do I change the order? Use the up and down arrows next to each file in the list. The result redraws immediately.
Can I merge more than two images? Yes, as many as you like. Drop them all at once or add more with the Add files button. In Grid mode set the number of columns and rows are added automatically.
Why is my merged image so big? The output keeps every source pixel. Five 4000 px wide photos in a row make a 20000 px image. Resize the sources first, or choose Smallest sizing.
Are the photos uploaded? No. The pictures are read and combined inside your browser; the page works offline once loaded.