Rotate a JPG online
Open one or more JPG or JPEG photos, turn them with the buttons, and save them as JPG. The output format is JPG and the quality is 92, which is almost impossible to tell from the original. You can switch to PNG or WebP at any time.
Fix sideways phone photos
A photo that is sideways in an email, a document or an upload form usually has an orientation tag that the program ignores. Rotate the picture to the position you want and save it. The turn is stored in the pixels, so every program shows it upright.
JPG quality after rotating
JPG is lossy, so the rotated picture is encoded again. At a quality of 90 or higher the change is hard to see. Keep the original file in case you need to start again. If you need a truly lossless turn of a JPG, command line tools such as jpegtran can rotate by 90 degrees without recompressing the picture, as long as the size is a multiple of the JPG block size.
Transparent pictures
JPG cannot store transparency, so transparent areas and the empty corners of a tilted picture are filled with the background colour, which is white by default.
Related tools
See rotate PNG, the main image rotator, crop JPG and JPG to WebP. To make the file smaller, use the image compressor.