The order is the whole problem

Every grid maker cuts squares. Most of them number the files the way you read a picture — top left first — and that is exactly the order that ruins the mural.

Your profile grid is not a canvas you paint on. It is a feed, drawn newest-first. The most recent post sits in the top-left cell, the one before it to its right, and so on, wrapping down the rows. So the tile that has to end up in the top-left corner is the last thing you publish, and the tile that ends up in the bottom-right corner has to be the first.

Post nine tiles in reading order and you do not get a slightly-off mural. You get the picture rotated a half turn, because reversing the order of a three-wide grid flips it both horizontally and vertically.

This tool names the files in posting order for that reason. post-01.png is the bottom-right tile and goes up first. The last number is the top-left tile and goes up last. Follow the numbers and the order takes care of itself — and the preview above puts the same number on every tile so you can see what belongs where before you download anything.

Choosing the number of rows

Three across is not a setting; the Instagram profile grid is three columns wide and always has been. Rows are yours to choose, and the count changes two things.

How much of your image survives. Tiles are square, so a three-row grid needs a square source and a two-row grid needs a 3:2 one. The further your image is from the shape your grid needs, the more gets trimmed off the long edges. If a wide photograph is what you have, two rows keeps far more of it than three.

How long the mural is incomplete. Every tile is a separate post. A nine-tile mural is nine posts, and until the last one goes up your profile shows a partial picture. Some people post the whole set in one sitting for that reason; others space them out and treat the half-finished grid as part of it.

What you get

A ZIP of square PNGs, named post-01.png upwards in the order you publish them. Post them as ordinary single-image posts, one at a time, lowest number first. They are unwatermarked, identically sized, and cut entirely by your own browser.