Pleasebox-sizing
Safe to usecssbox-sizing: border-box makes an element's declared width and height include its padding and border, which makes layouts far easier to reason about. It is supported everywhere and underpins nearly every modern CSS reset.
- Verdict
- Safe to use
- Category
- CSS features
- Browser support
- Can I Use
- Works in
- IE8+
Should you use box-sizing in 2026?
Supported in all major browsers.
See * { Box-sizing: Border-box } FTW if you want to set box-sizing: border-box safely as default behavior.