Sending four separate files to a chat assistant leaves the arrangement to the interface: order can shift, thumbnails shrink, and you end up describing positions in text instead of pointing at them. A merged grid removes that ambiguity. You decide that the top-left cell is the current version and that the top-right is the competitor, and whichever surface opens the file sees exactly that.

One composed grid is also the simplest way to keep a comparison honest. Four files attached separately are four loose items; nothing forces the assistant to treat them as a set. A single file with fixed cells reads as one object with four parts, which is what you want when the question is which of these is better, and why.

Where this pays off with Copilot: (1) Windows and Office troubleshooting, where a settings screen and an error dialog are merged so both are visible at once, (2) document summaries, where four pages of a contract go into a 2×2 with the page order made explicit, (3) spreadsheet work, where several chart screenshots sit in one file and the question is which trend dominates, (4) screenshot review, where the same screen at two zoom levels is shown side by side. The same technique is described for other assistants in our combine images for AI guide.

How to build it: open MergeFrame, drop your screenshots into the cells in reading order, pick a layout, leave a small gap so the boundaries are visible, and export at 2048px on the longest side. About 8px of separation is usually enough for a model to treat the cells as separate panels while keeping every label readable. PNG keeps interface text crisp; JPG export is there when file size matters more.

On the free plan you get 12 images per grid and 2 exports per day, with PNG and JPG output up to 4000px. Twelve images arrive in two batches, since one add takes up to six files. Everything is composited locally in your browser: no image is sent to a server, which matters when the screenshots contain internal documents.

When you write the prompt, name the cells. Something like: this is a 2×2 grid, top-left is the current settings screen, top-right is the error message, compare the two and tell me which setting is likely responsible. Naming the cells in the same order as the layout is one of the most effective changes you can make.