This tool turns images clockwise or anticlockwise and saves the rotated file. Use the quarter-turn buttons for photos that came out sideways or upside down: 90°, 180° and 270° turns move pixels without any resampling, so nothing is blurred and the width and height simply swap. You can select up to 30 images and rotate them all the same way in one run, then download them one by one or as a ZIP.
For a tilted horizon or a slightly skewed scan, the fine angle slider rotates by any amount between -45° and +45° in 0.1° steps (or type the angle). A rotation that isn't a quarter turn leaves empty corners, so you choose what happens to them: expand the canvas so the whole picture fits, keep the original size and trim the corners, or crop to the largest rectangle with no empty space, which is what a straightened photo usually wants. Empty corners can be transparent (PNG and WebP), white, black or any colour.
Limits: angled rotations resample the image, so very fine detail softens slightly, as in any editor. Saving re-encodes the file and removes EXIF data. Images over about 16.7 megapixels are scaled down to fit browser limits.