Grid Maker: Merge Images into One Picture

Side by side gives every image the same height and puts them in one row, which is what a before-and-after pair or a row of product colors needs. Stacked gives every image the same width and runs them down the page, the usual way to join a long chat or a set of tutorial screenshots into one tall picture. Grid fills rows left to right with the column count you choose, from 1 to 10, and adds rows as needed.

In a grid every cell is the same size, so photos of different shapes need a rule. Fill cell crops each image to its cell, giving a clean grid with no stray bars; Fit whole image shrinks each photo until it fits and paints the leftover space in the background color. Fill suits people and places, where trimming an edge rarely matters; Fit suits receipts, artwork and screenshots, where nothing may be cut.

The output size is plain arithmetic. With Match sizes on Auto, 1080 px cells in 3 columns with a 10 px gap make a grid 3 × 1080 + 2 × 10 = 3260 px wide, and nine of them a square of roughly the same height. That is sharp but heavy for a chat app, so set Max width to 2048 or 1080 px when the grid is headed for a phone; the finished image is scaled down as a whole, gaps included.

Format limits matter for long strips. JPEG cannot exceed 65,535 px on a side and WebP stops at 16,383 px, so twenty tall phone screenshots stacked at full width can outgrow WebP. For photos, JPG at Quality 85 is the usual choice; PNG keeps screenshot text crisp and, like WebP, can hold a transparent background. Posting the grid to Instagram as one image? Our guide to Instagram post and story sizes lists the ratios that avoid cropping.