How it works
Resizing by width alone keeps the aspect ratio, so nothing gets stretched — you set one number and the height follows.
1280 px is the usual sensible ceiling for images inside an article: wider than the column they sit in, so they stay sharp on high-density screens, without making the browser download pixels it will only throw away.
Frequently asked questions
How do I resize to 50%?+
Open the “half size” preset or enter width/height as half of the original dimensions shown after upload.