Dropresize

Dropresize is a free and easy-to-use app for batch resizing images. Just drag and drop your images into Dropresize, select the size you want and click the "Resize" button. Dropresize will automatically resize the images and save them back to the original folder.

Dropresize supports many different image formats, including JPG, PNG, GIF and BMP. You can also choose to resize the image by width, height or both sides. Dropresize also offers a wide range of image quality options, so you can adjust the size of your image and maintain its quality.