Grid & Carousel Splitter
Cut one picture into tiles for a profile grid, or into slides that read as a single continuous image when swiped. The pieces are worked out so they fit back together exactly — which is the part most splitters get wrong.
or drop one here — it stays on your device
Why exact matters
Cutting an image into three sounds trivial, and it is — until the width is not divisible by three. A 1081-pixel image divided by three is 360.33 pixels per tile, and the obvious thing to do is round that to 360. Do it and the last pixel column of the picture is simply gone. Round up instead and the tiles overlap, repeating a column.
One pixel does not sound like much. On a profile grid, where nine tiles sit against each other with hairline gaps, a repeated or missing column shows as a visible seam running down the picture — and it is exactly the kind of fault that is invisible while you are working and obvious once it is posted.
The fix is not to compute a tile width at all. Work out where each boundary falls across the whole image, rounding each one once, and take each tile as the space between two boundaries. Tiles then differ by at most a single pixel, and together they cover the original exactly with nothing lost and nothing repeated. Every cut here is checked against that before anything is exported.
Posting a grid in the right order
A profile grid fills from the top left, reading across. But posts appear newest first, so the tile that should end up top-left must be posted last. Each tile below is labelled with both its position and the order to upload it in, because getting this wrong means taking all nine down and starting again.
Carousel slides
Carousel mode cuts a wide image into slides that read as one continuous picture as you swipe. Feeds are strict about slide shape, so a panorama that is not the right width for the number of slides will be cropped by the platform — the tool works out the width that fits exactly and says so when yours does not match.