How wide is the default `<body>` margin?

css, html, margin

Solution

In most major browsers, the default margin is `8px` on all sides. It is defined in pixels by the `user-agent-stylesheet` your browser provides.

Some browsers allow you to create and use your own `user-agent-stylesheet`, but if you are developing a website, I would recommend staying away from changing this, since your users most likely will not have a modified stylesheet and would then see a different page than you do.

If you want to change it, you can just do this:

body {
  margin: 0px;
  padding: 0px;
  ...
}

But if you have a large project and want to be more complete, use normalize.css. It resets a lot of default values to be consistent across browsers.

Problem

What’s the default `margin` that HTML sets for its `<body>` tag? I noticed that there’s some automatic margin, but I’m wondering if anyone knows how much it is (and whether it’s in `px` or `%`, etc.).

Original source