The Paint editor on this site can mirror a picture or turn it around, either the whole canvas or only the part you have selected. A single dialog covers every case: a side-to-side flip, a top-to-bottom flip, a quarter, half or three-quarter turn, or a turn by any number of degrees you type in. Quarter turns can also be done with keys, without opening the dialog.
Open the Flip and Rotate dialog
All flips and turns begin in one place. Open the Image menu and choose Flip/Rotate, or press Ctrl+R. A dialog named Flip and Rotate comes up. It holds a group labeled Flip or rotate with three options: Flip horizontal, Flip vertical and Rotate by angle. When the dialog first opens, Flip horizontal is already picked. The dialog has two buttons, Okay, which applies your choice, and Cancel, which closes it without changing the picture. What gets changed depends on whether anything is selected. If a selection is active, only that area is flipped or turned. With nothing selected, the change goes to the entire picture.
Mirror the picture left to right or top to bottom
A flip makes a mirror image. Choose the direction that matches what you want to reverse.
- Press Ctrl+R, or go to Image > Flip/Rotate.
- Leave Flip horizontal selected to swap the left and right sides, so whatever faced left now faces right.
- Or pick Flip vertical to swap the top and bottom, so the top edge ends up at the bottom.
- Click Okay.
Rotate by 90, 180 or 270 degrees
The three preset angles give a quarter, half or three-quarter turn, and they count clockwise. That means 90° turns the picture a quarter to the right, and 270° ends up as a quarter turn to the left. A quarter turn in either direction trades the two sides of the canvas: the width becomes the height and the height becomes the width, so a wide picture comes out tall and a tall one comes out wide. A half turn with 180° leaves the canvas exactly as big as it was.
- Open Image > Flip/Rotate (Ctrl+R).
- Choose Rotate by angle. A short list of angles becomes active underneath it.
- Pick 90°, 180° or 270°. If you change nothing, 90° is used.
- Click Okay.
Turn the picture by any angle you type
For a turn that is not a multiple of 90 degrees, enter the angle yourself. The sign of the number sets the direction: a positive value turns the picture clockwise, and a negative value turns it counterclockwise. At angles other than 90, 180 and 270, the turned picture no longer fits the old rectangle, so the canvas is made larger to hold all of it. That leaves empty areas at the corners, which are filled in the secondary color. If you want them see-through instead, open Image > Attributes... (Ctrl+E) and choose Transparent in the Transparency group before you rotate. The turned pixels are drawn without smoothing, so edges can look jagged. If Degrees is the chosen option but its field is blank or holds something that is not a number, clicking Okay brings up a window titled Invalid Value, which reports that the Degrees value is not valid. Fix the entry and click Okay again.
- Open the dialog with Ctrl+R and choose Rotate by angle.
- Choose the Degrees option and type a number into its field. The Degrees field takes numbers from -360 to 360.
- Click Okay.
Rotate 90 degrees with the keyboard
Four key combinations give a quarter turn straight away, without the dialog. They follow the same rule as the menu command: a selection is turned if one exists, and otherwise the whole picture is.
- Ctrl+. or Ctrl+] turns the picture 90 degrees clockwise.
- Ctrl+, or Ctrl+[ turns the picture 90 degrees counterclockwise.
Flip or turn only a selected area
To mirror or rotate a single object rather than the whole drawing, make the selection with Select or Free-Form Select in the tool box first. Then open the dialog or press one of the rotation keys. Only the selected pixels change, and the rest of the canvas stays put. The flipped or turned area is still a selection afterward. To place it onto the picture for good, press Enter or Escape, pick a different tool, or click the gray space around the canvas. A flip or turn of the entire picture is a single entry in the undo history, so pressing Ctrl+Z once restores the picture as it was before.