Merge Images Online combines two or more individual images into a single picture directly inside your web browser. Whether you need side-by-side product comparisons, before-and-after renovation photos, or vertically stacked infographic panels, the tool calculates necessary canvas bounds and joins your files with customizable spacing and background color.

### How In-Browser Image Merging Works When you upload images, the tool creates an HTML5 canvas element sized to fit all imported graphics: - **Horizontal layout (side-by-side):** The canvas height matches the tallest image in your set, while total canvas width equals the combined width of all images plus your specified spacing gaps. Each image is centered vertically. - **Vertical layout (stacked):** The canvas width matches the widest image in your set, while total canvas height equals the combined height of all images plus spacing gaps. Each image is centered horizontally.

### Worked Example: Side-by-Side Before & After Comparison Consider merging two 1200x800 px landscape renovation photos into a single comparison asset: - **Input files:** 2 JPEG photos, each measuring 1200 px wide by 800 px high. - **Settings:** Layout set to Horizontal, spacing set to 20 px, background fill set to solid white (#FFFFFF). - **Calculated dimensions:** Total canvas width = 1200 + 1200 + 20 = 2420 px. Canvas height = 800 px. - **Canvas placement:** Image 1 is drawn at x = 0, y = 0. Image 2 is drawn at x = 1220 px, y = 0. The 20 px separator displays the clean white background. - **Export:** A 2420x800 px uncompressed PNG file exported locally in under 60 milliseconds.

### In-Browser Processing & Privacy Note All canvas drawing, pixel merging, and PNG generation execute locally in your web browser. Your private photos, confidential blueprints, and design screenshots are never uploaded to any remote server or third-party cloud service.