PicSizer

PicSizer is a very simple, neat, and straightforward application that lets you resize images both individually, one by one, and in batch, processing multiple photos at the same time.
Unfortunately, though it's a nice little free tool, it comes with some remarkable downsides.

For example, it can resize photos to no more than 1024 x 768 dimensions. Furthermore, the number of supported image file formats is rather small, as it can load, save, and process only BMP, PNG, JPG, TGA, and TIFF files. GIF files are supported only for loading, and other image formats than the aforementioned ones are not supported at all. Another thing that bothers me about this small application is the fact that it hasn't been updated since more than 10 years ago, so there's a high probability that some errors and compatibility issues might occur on newer systems like Windows 10. In my case, it was just a harmless script-related error and the app worked fine and did its job without any problem, but still, an app's latest version being 11 years old is a source of concern.

Anyway, despite its drawbacks, PicSizer still looks like a pretty decent tool, as it's free, it's neat and easy to use, and it also offers some handy additional features like the possibility to rotate the images, to rename the processed ones using predefined prefixes and suffixes, or to skip larger or smaller photos from the resizing process.

To sum it all up, PicSizer is a nice application despite its obvious flaws. The fact that it's free makes it deserve a try.