Upload your file: Click the "Choose File" button at the top. You can select either an image file (PNG, JPG, etc.) or a PDF file. If you upload a PDF, only the first page will be used.
Set your grid size: Use the "Rows" and "Cols" number boxes to choose how many pieces you want to cut your image into. For example, 2 rows and 3 columns will give you 6 pieces.
Adjust the grid lines: You will see red lines appear on your image. These lines show where the cuts will be made. You can click and drag any red line to move it. This lets you control exactly where each cut happens. The lines turn blue when you hover over them.
Slice your image: When you are happy with the grid position, click the "Slice and Dice" button. Your image will be cut into separate pieces and shown below.
Remove unwanted pieces: Look at the sliced images. If you do not want a particular piece, click the red "Delete" text underneath it. That piece will be removed and will not be included in your download.
Download your pieces: Click the green "Download All as ZIP" button. A ZIP file containing all your remaining image pieces will be downloaded to your computer. Each piece is saved as a PNG file.
Re-edit if needed: After slicing, the editor collapses. Click the "Edit Grid" button at the top to expand it again if you want to adjust your grid and slice again.