Image Splitter

An image splitter cuts one picture into several smaller ones along a grid. You give it a number of rows and columns, or a tile size in pixels, and it hands back every piece as its own file. Nothing is scaled, retouched or re-cropped: each tile is the exact pixels that were in that part of the original.

The usual reason is a layout somewhere else that wants pieces rather than one image. An Instagram profile grid is the common one: a single picture cut three by three and posted in reverse order reassembles into one large image across the profile. The same job comes up with printing a poster across several sheets, slicing a sprite sheet into frames, cutting a long screenshot into readable chunks, and splitting a scanned double page into two single pages.

The part that separates a good splitter from a bad one is what it does when the numbers do not divide evenly. A 1000 pixel wide image in three columns is 333.33 pixels each. Round each tile on its own and the pieces no longer line up: you get a seam, a duplicated column of pixels, or an image that is one pixel narrower than it started. This tool computes every cut from one rounded sequence of boundaries, so the right edge of one tile is the left edge of the next by construction, and the widths always add back to the original. On that 1000 pixel example the columns come out 333, 334 and 333.

In fixed-size mode the last row and column are usually smaller than the rest, because the image rarely divides into a whole number of tiles. That is deliberate. The alternative is cropping to a whole number of tiles, which quietly throws away the edge of your picture, and a tool whose job is to preserve pixels should not be the thing that loses them.

Everything runs in the browser. The image is read from your disk into the page, drawn onto a canvas, cut, and the pieces are packed into a ZIP without a server ever seeing the file. You can confirm it: open devtools, watch the network tab, and split something. No request carries the image. It also means the tool keeps working with the network off once the page has loaded, and that there is no copy of your picture to delete afterwards because none was made.