While Bootstrap uses em or rem for defining most sizes,
px are used for grid breakpoints and container widths. This is because
the viewport width is in pixels and does not change with the font
size.
| Extra small <576px |
Small ≥576px |
Medium ≥768px |
Large ≥992px |
Extra large ≥1200px |
Extra extra large ≥1400px |
|
|---|---|---|---|---|---|---|
| Grid behavior | Horizontal at all times | Collapsed to start, horizontal above breakpoints | ||||
| Max container width | None (auto) | 540px | 720px | 960px | 1140px | 1320px |
| Class prefix | .col- |
.col-sm- |
.col-md- |
.col-lg- |
.col-xl- |
.col-xxl- |
| # of columns | 12 | |||||
| Gutter width | 1.5rem (.75rem on left and right) | |||||
| Nestable | Yes | |||||
| Offsets | Yes | |||||
| Column ordering | Yes | |||||
Using a single set of .col-md-* grid classes, you can create a basic
grid system that starts out stacked on mobile devices and tablet devices (the extra
small to small range) before becoming horizontal on desktop (medium) devices. Place
grid columns within any .row.
Auto-layout for flexbox grid columns also means you can set the width of one column and have the sibling columns automatically resize around it. You may use predefined grid classes (as shown below), grid mixins, or inline widths. Note that the other columns will resize no matter the width of the center column.
Use flexbox alignment utilities to vertically and horizontally align columns.
Use flexbox alignment utilities to vertically and horizontally align columns.
Use flexbox alignment utilities to vertically and horizontally align columns.
Use .order- classes for controlling the visual order of
your content. These classes are responsive, so you can set the order by
breakpoint (e.g., .order-1.order-md-2). Includes support for
1 through 12 across all five grid tiers.
Move columns to the right using .offset-md-* classes. These classes
increase the left margin of a column by * columns. For example,
.offset-md-4 moves .col-md-4 over four columns.