Flip an image and mirror it

Horizontal mirrors the image left to right, swapping the two sides around a vertical center line. This is the one people reach for most: it turns a front-camera selfie back into the mirror view you are used to, and it flips the direction a subject is facing so they look the other way.

Vertical mirrors top to bottom instead, turning the image into an upside-down reflection of itself. It is much less common in everyday use, and the reason is worth knowing. Horizontal flips usually look plausible because the world is roughly symmetrical from left to right, so a mirrored face or landscape still reads as a real photograph. Vertical flips break gravity: shadows fall upwards, faces look wrong immediately, and the result reads as an effect rather than a photo. That makes vertical the right choice when you want it to be obvious, for a water-reflection composite or a deliberately disorienting graphic, and the wrong choice when you are trying to quietly fix an image.

One case where vertical is the practical answer: film and document scans that were fed into the scanner the wrong way up, or images captured through a mirror or prism rig. There the image really is upside down as data, not as artistic choice, and a vertical flip puts it back.

These two get confused constantly, and the tell is what happens to writing. A flip mirrors the image, so text comes out backwards and unreadable. A rotation turns the image around its center, so text stays readable, just sideways or upside down.

The practical test: look at the problem and ask whether the photo is facing the wrong way or oriented the wrong way. A portrait shot that came out of the camera lying on its side is an orientation problem, and the answer is the rotate tool. A photo where the subject faces left and you need them facing right is a direction problem, and the answer is a horizontal flip here.

The two are not exclusive. A vertical flip produces the same pixel arrangement as a horizontal flip plus a 180 degree rotation, which is why an upside-down-looking result sometimes comes from the wrong one of these being applied twice. If you need both operations, add a Rotate step next to the Flip step and they run together on one upload, in the order the chips appear.

Drop in as many files as you like and every one is mirrored the same way. There is no separate batch mode to switch on, and no cap on the number of files. They are processed one after another rather than all at once, so a large batch of big photos takes a while, and the progress is shown per file as it goes.

Each file keeps its own format through the batch, so a folder holding a mix of JPEGs and PNGs comes out as the same mix rather than being flattened to one format. Download them individually, or take the whole set as a single ZIP.

Because everything runs in your browser, the practical limit is your own machine's memory rather than an upload quota. Nothing is sent anywhere, which is also why a batch of a hundred photos costs no more than a batch of one in terms of privacy.