ReduceImages works by uploading your picture to process it, and its paid plans list "No advertising" as a benefit, so the free tier carries ads. A browser-based image resizer scales the photo on your own device, ad free, with nothing uploaded.
ReduceImages is a straightforward online resizer, and its own flow uploads your image to process it, while its premium plans list "No advertising" among the paid benefits, which means the free tier shows ads. A client-side resizer never sends the file anywhere: the browser reads the image, scales it to your target dimensions, and downloads the result, with no ads on the tool page.
Local resizing is the safer default for a screenshot with personal information, an unpublished shot, or any photo of a person, because nothing is uploaded and there is nothing to delete afterward. You still get exact pixel dimensions with an optional locked aspect ratio, and there are no ads competing for your attention while you work.
No. Resizing happens in your browser, so the image never leaves your device.
No. The tool page is ad free, with no premium tier to remove them.
Yes. Lock the ratio to scale proportionally, or set a custom width and height.