Move, resize, and snap user slices

You can move and resize user slices in Photoshop, but not in the Save For Web & Devices dialog box.

Select one or more user slices.
Do one of the following:
- To move a slice, move the pointer inside the slice selection border, and drag the slice to a new position. Press Shift to restrict movement to a vertical, horizontal, or 45° diagonal line.
- To resize a slice, grab a side or a corner handle of the slice, and drag. If you select and resize adjacent slices, common edges shared by the slices are resized together.

Select one or more user slices.
Click the Options button in the options bar. You can also double-click a slice to show the options.
In the Dimensions area of the Slice Options dialog box, change one or more of the following options:
X

Specifies the distance in pixels between the left edge of the slice and the origin of the ruler in the document window.
Y

Specifies the distance in pixels between the top edge of the slice and the origin of the ruler in the document window.
Note: The default origin of the ruler is the upper left corner of the image.

W

Specifies the width of the slice.
H

Specifies the height of the slice.

Select the options you want from the View > Snap To submenu.
Choose View > Snap. A check mark indicates that the option is turned on.
Move your selected slices as desired. The slices snap to any of your chosen objects within 4 pixels.

Photoshop