You might be aware that Google has introduced its own image format Webp for web, if you are a webmaster then you might consider using WebP images on your website as these provides better file compression and quality than other popular formats like jpg and png.
But there is an issue, not all modern web browser supports this format, at this time only Google Chrome supports WebP format, which means if you open any website which is using WebP images on it in any other browser except than Chrome then you wont be able to see it. For this you can consider serving WebP images to Chrome users and for rest browser serve traditional formats.
If you had planned to serve WebP images to supported web browser then you must have to convert your images to WebP format. You can do this by WebPconv which is a freeware tool for Windows which allows you to convert images to WebP format.
Interface of this tool is simple and you can convert images without any issue, once you had downloaded and install just drag and drop your images which you wish to convert. This tool can convert bulk images at once but we suggest you to test few images and if you are satisfied with quality then convert in bulk.
You can change default compression factor from 75 to something else by heading to setting, there are enable lossless conversions and an auto filter options are there which are disabled by default you can use them according to your need.
After playing with setting, drag and drop few images and convert them, WebPconv will display original size, new size and change in percent in its interface.
One thing which we missed in it is preview mode, there is no way to check images before converting them. To check quality you have to convert them first and then only you can find out its quality.