Can I watermark a whole folder at once?

Yes. Select multiple images and the same settings are applied to all of them.

What opacity should I use?

Low enough not to ruin the image, high enough to survive a screenshot — around 30 to 40 percent tiled across the picture is the usual compromise.

Tile text or a logo across an image with opacity, angle and spacing. Batch a folder.

Runs in your browser — nothing uploaded

Can I watermark a whole folder at once?: Yes. Select multiple images and the same settings are applied to all of them.
What opacity should I use?: Low enough not to ruin the image, high enough to survive a screenshot — around 30 to 40 percent tiled across the picture is the usual compromise.

PNG, JPEG and WebP in any direction, with a background colour for transparency.

Resize and re-encode photos to hit a target size, with before and after shown.

Cut the subject out of a photo and get a clean transparent PNG, or drop in a new colour.

Enlarge a small image 2× with a neural network that reconstructs detail instead of blurring it.