How to fix a sideways photo

The photo is not sideways. The instructions are.

When you turn your phone to take a portrait photograph, the camera sensor does not rotate. It records the scene in its own fixed orientation and then writes a small note into the file’s metadata: this image should be rotated 90 degrees clockwise when displayed.

That note is the EXIF orientation tag. It has eight possible values, covering the four rotations and their mirrored versions. Your phone’s gallery reads it and shows the photo the right way up, which is why everything looks correct until the file goes somewhere else.

Why other software gets it wrong

Reading that tag is optional, and plenty of software does not bother. Older desktop applications, some email clients, print services, and a great many web upload handlers read the pixels and ignore the metadata entirely. They display exactly what the sensor recorded — which is your photograph on its side.

Worse, some software strips metadata while processing. If a system removes EXIF for privacy reasons but does not apply the rotation first, the note vanishes and the image is now permanently, genuinely sideways with no way to know it was ever meant to be otherwise. This is the most common cause of a photograph that was fine a moment ago and is not any more.

The permanent fix

Bake the rotation into the pixels. That means decoding the image, applying the rotation the tag describes, and saving the result — so the pixels themselves are upright and the tag is no longer needed by anyone.

FileBelow does this to every image it opens, before anything else happens. It reads the orientation tag directly out of the file rather than relying on the browser, applies the transform, and works from the corrected image. Whatever you download is upright in software that reads metadata and in software that does not.

This is deliberately not left to the browser. Browsers do offer to apply orientation during decoding, but support has been uneven historically, and the tag also has to be reported back to you. Having two sources of truth about rotation is precisely how images end up rotated twice, or not at all.

Doing it without a tool

On Windows, opening the photo in Photos and using the rotate button, then saving, will usually normalise it — rotate it four times if it already looks correct, so the file is re-saved either way. On macOS, Preview’s Tools menu has the same effect.

Be aware that some viewers only update the tag rather than the pixels, which does not help. If a photograph still appears sideways elsewhere after you have rotated it, the software adjusted the note rather than the picture.

When it is mirrored rather than rotated

Front-facing cameras often store a mirrored orientation, because the preview is mirrored so it behaves like a mirror while you frame the shot. Four of the eight orientation values describe mirrored states, and software that half-understands the tag can produce a photograph that is both rotated and flipped.

Text in the image is the giveaway: if it reads backwards, the image has been mirrored rather than merely rotated, and applying the correct orientation fixes both at once.