Merge Images (Combine Photos)

Putting two pictures side by side is the quickest way to show a before-and-after, compare two products or send several screenshots as one file. This tool joins two or more images horizontally, vertically or in a grid, scales them to a common height or width so the edges line up, and can add spacing and a background. Long chat captures can be stitched into one tall image. It all runs in your browser.

How to use this tool

1. Choose the images in the order they should appear.
2. Pick side by side, stacked, or a grid with a number of columns.
3. Choose size matching: match the smallest to avoid blurry enlargement, the largest, the first image, or keep original sizes.
4. Set the alignment, spacing and background (or transparent), then download the merged image.

Formula

Side by side, matched heights: width = Σ (wᵢ × T ÷ hᵢ) + (n − 1) × spacing, height = T

T is the common height (the smallest, largest or first image’s height). Stacking works the same way with widths. Grids size each column to its widest image and each row to its tallest. Browsers limit canvas size: about 268 megapixels on desktop and roughly 16.7 megapixels on iPhones and iPads, so very long stitches are checked first and you get a clear message instead of a blank file.

Example

A 1200 × 800 px photo and a 600 × 900 px photo placed side by side with match the smallest height (800 px): the second becomes 533 × 800 px, so the result is 1200 + 533 = 1733 × 800 px. Stacking three 1170 × 2532 px phone screenshots gives 1170 × 7596 px (8.9 MP), which fits even on an iPhone.