The free image converter software also supports batch conversion. That is to say, you can add many images even from different folders to the converting list. All the files in the converting list can be converted at the same time as your settings. Make thumbnail
You can set the size of the target images, so you can directly set it as thumbnail size in Size page.
Add watermark to your images, and you don't need to worry that someone will take the photos for their own use when sharing photos, especially posting them online or emailing them. You can set the font of the text watermark and the position of the watermark. You can not only input text as watermark, but also select an image as watermaker in version 2.0.
Preview the files
You can preview images including current file format, size and watermark before conversion.