Over the years I’ve seen a number of really neat web sites, in terms of what they were able to accomplish in a browser. Then I saw https://www.photopea.com/, and it really takes the cake. It is an image editor, think Adobe Photoshop or GNU Image Manipulation Program (GIMP), but in a web page. This is one serious piece of work.
A few months ago the author, Ivan Kutskir, did an AMA ( Ask Me Anything) on Reddit. One person brought up the issue of licensing and rights for uploading the images to edit them. The response took this to the next level:
Photopea runs completely in your device, just like Gimp or Photoshop do. It does not upload any of your files to the internet.
You can load www.Photopea.com, disconnect from the internet and keep using it completely offline. None of your files ever leaves your computer.
That is some impressive JavaScript action.