Quarter turns vs free angle
The tool offers two kinds of rotation, and they suit different jobs.
90, 180 and 270 degrees are for photos that are simply the wrong way round: a portrait shot that shows up sideways, a document scanned upside down, a screenshot from a phone held in landscape. These turns are exact. Every pixel lands on a new spot with no blending, so the image stays as sharp as before. Width and height swap on 90 and 270 degree turns.
Free angle (any value from -180 to 180) is for straightening. A horizon that tilts by two degrees, a building that leans, or a receipt photographed at a slant can all be corrected. Because the pixels no longer line up with the grid, they are resampled, which softens fine detail very slightly. For small corrections this is rarely noticeable.
Dealing with the corners
When you rotate by an angle like 7 degrees, the original rectangle no longer fits a straight frame. The canvas grows to hold the whole picture, and four triangular gaps appear. You have two choices:
- Fill color. Pick white for documents, black for photos shown on dark pages, or any brand color. This works for every output format.
- Transparent. The corners stay clear and the file is saved as PNG, since JPG cannot store transparency. Handy for stickers, product cutouts and graphics you will place on a colored background.
If you want a clean rectangular photo with no corners at all, crop the result afterward so only the picture area remains.
Why photos appear rotated in the first place
Most cameras and phones do not actually turn the image data when you hold the device sideways. They store it in the sensor’s native direction and write an orientation flag in the EXIF metadata. Photo apps read the flag; some upload forms, older software and email clients do not, so the photo shows up on its side.
Your browser applies that flag when it opens the file, so the preview shows the image the way your phone did. When you rotate and download, the orientation is written into the pixels themselves. The output looks the same in every program, regardless of metadata.
Tips and troubleshooting
- Straightening: look for a reliable straight line, such as the horizon, a door frame or a table edge, and adjust until it is level. Go slowly; one degree makes a visible difference.
- Rotating text documents: use the 90 degree options rather than the slider so the text stays crisp.
- Large files: images can be up to 8,000 pixels per side. Free rotation enlarges the canvas, so a very large image at 45 degrees may hit that limit. Resize first if needed.
- Undo a turn: rotate the opposite way. 90 followed by 270 returns to the original.