Flip, mirror, rotate: what is the difference?
- Flip horizontal swaps left and right, like a mirror. A person who parts their hair on the left now parts it on the right.
- Flip vertical swaps top and bottom, like the reflection of a building in still water.
- Rotate 180 degrees turns the picture upside down. It equals one horizontal and one vertical flip together.
- Rotate 90 degrees turns the picture on its side, so a landscape picture becomes a portrait one.
The difference matters for anything with a direction. Writing, numbers, logos and a watch face keep their direction after a rotation and are reversed after a flip. A flip changes the picture, a rotation only changes how it is held. If your picture is upside down, rotate it by 180 degrees. If your picture is the wrong way round, like a mirrored selfie, flip it.
Mirrored selfies and mirrored scans
A front camera usually shows you a mirror image while you frame the shot, because that feels natural. What gets saved depends on the phone and its settings: some save the picture the way other people see you, some save the mirrored version, and several phones have a setting for it. If the writing on a shirt, a sign or a mug comes out backwards in your photo, flip it horizontally and it reads correctly again.
Scans and photos of documents can end up mirrored too, for example when you photograph a page through a window or from the back. A horizontal flip fixes that. If the page is also upside down, add a rotation by 180 degrees.
Flipping for design
Designers mirror photos to change which way a person looks, so that the face points toward the text or the centre of a page instead of out of it. Flipping is safe for a face or a landscape, but not for anything with writing, a logo, a clock or a left-hand-drive car, which look wrong when reversed. Flipping a picture of a real place changes the real layout, so a map, a building with a sign or a landmark stops matching reality.
A flip does not change the size of the picture. A 4000 by 3000 pixel picture is still 4000 by 3000 afterwards, and nothing is cropped or blurred, because no pixel is recalculated.
Flipping a whole set
A set of product photos or portraits often has subjects that face different ways. Flip the ones that point the wrong way and every picture in a gallery or on a page faces the same direction. Add all the pictures, flip them in one run, and download one ZIP. Names get "-flipped" added ("-rotated" if you also turned the pictures), so the originals stay as they are. To flip only some of them, run those separately.
Flipping twice brings the picture back. For a PNG that is exactly the original pixels. For a JPG each save compresses again, so flip a JPG once and keep the original instead of flipping the flipped file.
Flipping and the file
Saving a flipped JPG writes a new JPG, so the picture is compressed once more. At the starting quality of 95 the loss is very small, and PNG is exact. Camera details, date and GPS location are removed by default; switch Metadata to Keep to copy them from JPG, PNG and WebP originals. A photo that was stored sideways is turned upright before it is flipped, and the result carries no rotation tag.
Pictures up to 100 megapixels are accepted. A batch runs several pictures at a time and large ones one at a time, a file that fails is listed with a reason, and Cancel leaves the finished files alone.