Bootstrap’s grid system uses a series of containers, rows, and columns to layout and align content. It’s built with flexbox and is fully responsive. While Bootstrap uses ems or rems for defining most sizes, pxs 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. See how aspects of the Bootstrap grid system work across multiple devices with a handy table. For a complete set of examples please refer to this page.

Equal-width

Utilize breakpoint-specific column classes for easy column sizing without an explicit numbered class like .col-sm-6. For example, here are two grid layouts that apply to every device and viewport, from xs to xl. Add any number of unit-less classes for each breakpoint you need and every column will be the same width.

Setting one column width

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.

Variable width content

Use .col-{breakpoint}-auto classes to size columns based on the natural width of their content. In this case the browser will calculate and select a width for the grid column. Also you can use optional flex helper classes to add custom grid appearance and mix other grid column classes with auto width.

Equal-width multi-row

Create equal-width columns that span multiple rows by inserting a .w-100 where you want the columns to break to a new line. Make the breaks responsive by mixing the .w-100 with some responsive display utilities. Equal-width columns can be broken into multiple lines, but there was a Safari flexbox bug that prevented this from working without an explicit flex-basis or border.

All breakpoints

For grids that are the same from the smallest of devices to the largest, use the .col and .col-* classes. Specify a numbered class when you need a particularly sized column; otherwise, feel free to stick to .col.

Stacked to horizontal

Using a single set of .col-sm-* classes, you can create a basic grid system that starts out stacked on extra small devices before becoming horizontal on desktop (medium) devices.

Mix and match

Don’t want your columns to simply stack in some grid tiers? Use a combination of different classes for each tier as needed. For a better idea of how it all works - First row: Stack the columns on mobile by making one full-width and the other half-width. Second row: Columns start at 50% wide on mobile and bump up to 33.3% wide on desktop. Third row: Columns are always 50% wide, on mobile and desktop

No gutters

The gutters between columns in our predefined grid classes can be removed with .g-0. This removes the negative margins from .row and the horizontal padding from all immediate children columns. Note that column overrides are scoped to only the first children columns and are targeted via attribute selector. While this generates a more specific selector, column padding can still be further customized with spacing utilities.

Column wrapping

If more than 12 columns are placed within a single row, each group of extra columns will, as one unit, wrap onto a new line.

Column breaks

Use .col-{breakpoint}-auto classes to size columns based on the natural width of their content. In this case the browser will calculate and select a width for the grid column. Also you can use optional flex helper classes to add custom grid appearance and mix other grid column classes with auto width.

Order classes

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-lg-2). Includes support for 1 through 12 across all five grid tiers.

There’s also a responsive .order-first class that quickly changes the order of one element by applying order: -1. This class can also be intermixed with the numbered .order-* classes as needed.

You can offset grid columns in two ways: our responsive .offset- grid classes and our margin utilities. Grid classes are sized to match columns while margins are more useful for quick layouts where the width of the offset is variable.

Offset classes

Move columns to the right using .offset-lg-* classes. These classes increase the left margin of a column by * columns. For example, .offset-lg-4 moves .col-lg-4 over four columns.

In addition to column clearing at responsive breakpoints, you may need to reset offsets:

Margin utilities

With the move to flexbox in v4, you can use margin utilities like .ms-auto to force sibling columns away from one another.

To nest your content with the default grid, add a new .row and set of .col-sm-* columns within an existing .col-sm-* column. Nested rows should include a set of columns that add up to 12 or fewer (it is not required that you use all 12 available columns).