Picture Resizer is a free tool for batch resizing of JPEG images. Picture Resizer is unique in many ways, first it does not have any interface to resize as its a command line resize and second is that it can add a context menu to Windows for resizing images. By default when the program is downloaded, the file name is PhotoResize400.exe, in which 400 means to size to which images will be resized. You can rename the application to PhotoResize500.exe which makes the image resizing to 500px.
When you execute the exe file, it provides you the option to add context menu to Windows. Once added, images can be resized by right click. For batch image resizing, select all the photos and drag and drop to the exe file of Picture Resizer. It resizes all the images and saves in the parent folder itself.
The application has many command line parameters and arguments for resizing and details of which can be got from the website.