Flexbox Quickly manage the layout, alignment, and sizing of grid columns, navigation, components, and more with a full suite of responsive flexbox utilities.
The flexbox behaviours are an adaptation from the core bootstrap 4 CSS system. To learn further about its responsive behaviours please head over to the official documentation for flexbox.
Enable flex behaviors
Apply display
utilities to create a flexbox container and transform direct children elements into flex items. Flex containers and items are able to be modified further with additional flex properties.
d-flex
d-inline-flex
Direction Set the direction of flex items in a flex container with direction utilities. In most cases you can omit the horizontal class here as the browser default is row. However, you may encounter situations where you needed to explicitly set this value (like responsive layouts).
Use .flex-row
to set a horizontal direction (the browser default), or .flex-row-reverse
to start the horizontal direction from the opposite side.
Use .flex-column
to set a vertical direction, or .flex-column-reverse
to start the vertical direction from the opposite side.
Justify Content
justify-content
utilities on flexbox containers to change the alignment of flex items on the main axis (the x-axis to start, y-axis if flex-direction: column
). Choose from start
(browser default), end
, center
, between
, or around
.
Align items
Use align-items
utilities on flexbox containers to change the alignment of flex items on the cross axis (the y-axis to start, x-axis if flex-direction: column
).
Choose from start
, end
, center
, baseline
, or stretch
(browser default).
Responsive variations also exist for align-items
.
Align self
Use align-self
utilities on flexbox items to individually change their alignment on the cross axis (the y-axis to start, x-axis if flex-direction: column
).
Choose from the same options as align-items: start
, end
, center
, baseline
, or stretch
(browser default).
Fill
Use the .flex-fill
class on a series of sibling elements to force them into widths equal to their content (or equal widths if their content does not surpass their border-boxes) while taking up all available horizontal space.
Grow and shrink
Use .flex-grow-*
utilities to toggle a flex item’s ability to grow to fill available space. In the example below, the .flex-grow-1
elements uses all available space it can, while allowing the remaining two flex items their necessary space.
Choose from the same options as align-items: start
, end
, center
, baseline
, or stretch
(browser default).
Use .flex-shrink-*
utilities to toggle a flex item’s ability to shrink if necessary. In the example below, the second flex item with .flex-shrink-1
is forced to wrap it’s contents to a new line, “shrinking” to allow more space for the previous flex item with .w-100
.
Auto margins
Flexbox can do some pretty awesome things when you mix flex alignments with auto margins. Shown below are three examples of controlling flex items via auto margins: default (no auto margin), pushing two items to the right (.mr-auto
), and pushing two items to the left (.ml-auto
).
Unfortunately, IE10 and IE11 do not properly support auto margins on flex items whose parent has a non-default justify-content value. See this StackOverflow answer.