As long as you have a browser and an Internet environment, you can use it on your PC or smartphone. You don't need to register as a member or log in. You don't need to download the software. You can use the function as soon as you visit the site.
All of these functions are very simple to use, basically simply upload the original image and download the converted image. Even features that require fine-tuning can be handled as intuitively as possible without prior knowledge.