Bootstrap v5.2.0 features a subtle design update for a handful of components and properties across the project, **most notably through refined `border-radius` values on buttons and form controls**. Our documentation also has been updated with a new homepage, simpler docs layout that no longer collapses sections of the sidebar, and more prominent examples of [Bootstrap Icons](https://icons.getbootstrap.com).
**We've updated nearly all our components to use CSS variables.** While Sass still underpins everything, each component has been updated to include CSS variables on the component base classes (e.g., `.btn`), allowing for more real-time customization of Bootstrap.
The following components are now built with CSS variables:
Read more about CSS variables in each component on their respective documentation pages. The rest of our components, forms, and more will be updated by v5.3.
Our CSS variable usage will be somewhat incomplete until Bootstrap 6. While we'd love to fully implement these across the board, they do run the risk of causing breaking changes. For example, setting `$alert-border-width: var(--bs-border-width)` in our source code breaks potential Sass in your own code if you were doing `$alert-border-width * 2` for some reason.
As such, wherever possible, we will continue to push towards more CSS variables, but please recognize our implementation may be slightly limited in v5.
**Bootstrap v5.2.0 introduced a new Sass file with `_maps.scss`.** It pulls out several Sass maps from `_variables.scss` to fix an issue where updates to an original map were not applied to secondary maps that extend them. For example, updates to `$theme-colors` were not being applied to other theme maps that relied on `$theme-colors`, breaking key customization workflows. In short, Sass has a limitation where once a default variable or map has been _used_, it cannot be updated. _There's a similar shortcoming with CSS variables when they're used to compose other CSS variables._
This is why variable customizations in Bootstrap have to come after `@import "functions"`, but before `@import "variables"` and the rest of our import stack. The same applies to Sass maps—you must override the defaults before the defaults get used. The following maps have been moved to the new `_maps.scss`:
-`$theme-colors-rgb`
-`$utilities-colors`
-`$utilities-text`
-`$utilities-text-colors`
-`$utilities-bg`
-`$utilities-bg-colors`
-`$negative-spacers`
-`$gutters`
Your custom Bootstrap CSS builds should now look something like this with a separate maps import.
- Expanded [`border-radius` utilities]({{< docsref "/utilities/borders#sizes" >}}) to include two new sizes, `.rounded-4` and `.rounded-5`, for more options.
- **Introduced new `$enable-container-classes` option. —** Now when opting into the experimental CSS Grid layout, `.container-*` classes will still be compiled, unless this option is set to `false`. Containers also now keep their gutter values.
- **Thicker table dividers are now opt-in. —** We've removed the thicker and more difficult to override border between table groups and moved it to an optional class you can apply, `.table-group-divider`. [See the table docs for an example.]({{< docsref "/content/tables#table-group-dividers" >}})
- **Added experimental support for [CSS Grid layout]({{< docsref "/layout/css-grid" >}}). —** This is a work in progress, and is not yet ready for production use, but you can opt into the new feature via Sass. To enable it, disable the default grid, by setting `$enable-grid-classes: false` and enable the CSS Grid by setting `$enable-cssgrid: true`.
- **Updated navbars to support offcanvas. —** Add [offcanvas drawers in any navbar]({{< docsref "/components/navbar#offcanvas" >}}) with the responsive `.navbar-expand-*` classes and some offcanvas markup.
- **Added new [placeholder component]({{< docsref "/components/placeholders/" >}}). —** Our newest component, a way to provide temporary blocks in lieu of real content to help indicate that something is still loading in your site or app.
- **Collapse plugin now supports [horizontal collapsing]({{< docsref "/components/collapse#horizontal" >}}). —** Add `.collapse-horizontal` to your `.collapse` to collapse the `width` instead of the `height`. Avoid browser repainting by setting a `min-height` or `height`.
- **Added new stack and vertical rule helpers. —** Quickly apply multiple flexbox properties to quickly create custom layouts with [stacks]({{< docsref "/helpers/stacks/" >}}). Choose from horizontal (`.hstack`) and vertical (`.vstack`) stacks. Add vertical dividers similar to `<hr>` elements with the [new `.vr` helpers]({{< docsref "/helpers/vertical-rule/" >}}).
- **Added new global `:root` CSS variables. —** Added several new CSS variables to the `:root` level for controlling `<body>` styles. More are in the works, including across our utilities and components, but for now read up [CSS variables in the Customize section]({{< docsref "/customize/css-variables/" >}}).
- **Overhauled color and background utilities to use CSS variables, and added new [text opacity]({{< docsref "/utilities/text#opacity" >}}) and [background opacity]({{< docsref "/utilities/background#opacity" >}}) utilities. —** `.text-*` and `.bg-*` utilities are now built with CSS variables and `rgba()` color values, allowing you to easily customize any utility with new opacity utilities.
- **Added new snippet examples based to show how to customize our components. —** Pull ready to use customized components and other common design patterns with our new [Snippets examples]({{< docsref "/examples#snippets" >}}). Includes [footers]({{< docsref "/examples/footers/" >}}), [dropdowns]({{< docsref "/examples/dropdowns/" >}}), [list groups]({{< docsref "/examples/list-groups/" >}}), and [modals]({{< docsref "/examples/modals/" >}}).
Want more information? [Read the v5.1.0 blog post.](https://blog.getbootstrap.com/2021/08/04/bootstrap-5-1-0/)
- **Popovers and tooltips now use CSS variables.** Both components have been updated to use CSS variables on their base classes, `.popover` and `.tooltip`. Some CSS variables have been updated from their Sass counterparts to reduce the number of variables. As a result, three variables have been deprecated in this release: `$popover-arrow-color`, `$popover-arrow-outer-color`, and `$tooltip-arrow-color`.
- Added [new Customize section]({{< docsref "/customize/overview" >}}), replacing [v4's Theming page](https://getbootstrap.com/docs/4.6/getting-started/theming/), with new details on Sass, global configuration options, color schemes, CSS variables, and more.
- Reorganized all form documentation into [new Forms section]({{< docsref "/forms/overview" >}}), breaking apart the content into more focused pages.
- Similarly, updated [the Layout section]({{< docsref "/layout/breakpoints" >}}), to flesh out grid content more clearly.
- We've ditched the default Sass map merges to make it easier to remove redundant values. Keep in mind you now have to define all values in the Sass maps like `$theme-colors`. Check out how to deal with [Sass maps]({{< docsref "/customize/sass#maps-and-loops" >}}).
-<spanclass="badge bg-danger">Breaking</span> Renamed `color-yiq()` function and related variables to `color-contrast()` as it's no longer related to YIQ color space. [See #30168.](https://github.com/twbs/bootstrap/pull/30168/)
-<spanclass="badge bg-danger">Breaking</span> Media query mixins parameters have changed for a more logical approach.
-`media-breakpoint-down()` uses the breakpoint itself instead of the next breakpoint (e.g., `media-breakpoint-down(lg)` instead of `media-breakpoint-down(md)` targets viewports smaller than `lg`).
- Similarly, the second parameter in `media-breakpoint-between()` also uses the breakpoint itself instead of the next breakpoint (e.g., `media-between(sm, lg)` instead of `media-breakpoint-between(sm, md)` targets viewports between `sm` and `lg`).
-<spanclass="badge bg-danger">Breaking</span> Dropped `color()`, `theme-color()`, and `gray()` functions in favor of variables. [See #29083](https://github.com/twbs/bootstrap/pull/29083).
-<spanclass="badge bg-danger">Breaking</span> Renamed `theme-color-level()` function to `color-level()` and now accepts any color you want instead of only `$theme-color` colors. [See #29083](https://github.com/twbs/bootstrap/pull/29083) **Watch out:**`color-level()` was later on dropped in `v5.0.0-alpha3`.
-<spanclass="badge bg-danger">Breaking</span> Renamed `$enable-prefers-reduced-motion-media-query` and `$enable-pointer-cursor-for-buttons` to `$enable-reduced-motion` and `$enable-button-pointers` for brevity.
-<spanclass="badge bg-danger">Breaking</span> Removed the `bg-gradient-variant()` mixin. Use the `.bg-gradient` class to add gradients to elements instead of the generated `.bg-gradient-*` classes.
-<spanclass="badge bg-danger">Breaking</span> Renamed `scale-color()` function to `shift-color()` to avoid collision with Sass's own color scaling function.
- The color system which worked with `color-level()` and `$theme-color-interval` was removed in favor of a new color system. All `lighten()` and `darken()` functions in our codebase are replaced by `tint-color()` and `shade-color()`. These functions will mix the color with either white or black instead of changing its lightness by a fixed amount. The `shift-color()` will either tint or shade a color depending on whether its weight parameter is positive or negative. [See #30622](https://github.com/twbs/bootstrap/pull/30622) for more details.
- Improved color contrast. Bumped color contrast ratio from 3:1 to 4.5:1 and updated blue, green, cyan, and pink colors to ensure WCAG 2.1 AA contrast. Also changed our color contrast color from `$gray-900` to `$black`.
- **Improved gutters.** Gutters are now set in rems, and are narrower than v4 (`1.5rem`, or about `24px`, down from `30px`). This aligns our grid system's gutters with our spacing utilities.
- Added new [gutter class]({{< docsref "/layout/gutters" >}}) (`.g-*`, `.gx-*`, and `.gy-*`) to control horizontal/vertical gutters, horizontal gutters, and vertical gutters.
-<spanclass="badge bg-danger">Breaking</span> Dropped several `.order-*` classes that often went unused. We now only provide `.order-1` to `.order-5` out of the box.
-<spanclass="badge bg-danger">Breaking</span> Dropped the `.media` component as it can be easily replicated with utilities. [See #28265](https://github.com/twbs/bootstrap/pull/28265) and the [flex utilities page for an example]({{< docsref "/utilities/flex#media-object" >}}).
-<spanclass="badge bg-danger">Breaking</span>`bootstrap-grid.css` now only applies `box-sizing: border-box` to the column instead of resetting the global box-sizing. This way, our grid styles can be used in more places without interference.
- **[RFS]({{<docsref"/getting-started/rfs">}}) is now enabled by default.** Headings using the `font-size()` mixin will automatically adjust their `font-size` to scale with the viewport. _This feature was previously opt-in with v4._
-<spanclass="badge bg-danger">Breaking</span> Overhauled our display typography to replace our `$display-*` variables and with a `$display-font-sizes` Sass map. Also removed the individual `$display-*-weight` variables for a single `$display-font-weight` and adjusted `font-size`s.
-<spanclass="badge bg-danger">Breaking</span>`.thead-light` and `.thead-dark` are dropped in favor of the `.table-*` variant classes which can be used for all table elements (`thead`, `tbody`, `tfoot`, `tr`, `th` and `td`).
-<spanclass="badge bg-danger">Breaking</span> The `table-row-variant()` mixin is renamed to `table-variant()` and accepts only 2 parameters: `$color` (color name) and `$value` (color code). The border color and accent colors are automatically calculated based on the table factor variables.
-<spanclass="badge bg-danger">Breaking</span>`.text-*` utilities do not add hover and focus states to links anymore. `.link-*` helper classes can be used instead. [See #29267](https://github.com/twbs/bootstrap/pull/29267)
-<spanclass="badge bg-danger">Breaking</span>~~`<hr>` elements now use `height` instead of `border` to better support the `size` attribute. This also enables use of padding utilities to create thicker dividers (e.g., `<hr class="py-1">`).~~
- Added `$enable-smooth-scroll`, which applies `scroll-behavior: smooth` globally—except for users asking for reduced motion through `prefers-reduced-motion` media query. [See #31877](https://github.com/twbs/bootstrap/pull/31877)
- Horizontal direction specific variables, utilities, and mixins have all been renamed to use logical properties like those found in flexbox layouts—e.g., `start` and `end` in lieu of `left` and `right`.
- **Added new floating forms!** We've promoted the Floating labels example to fully supported form components. [See the new Floating labels page.]({{< docsref "/forms/floating-labels" >}})
-<spanclass="badge bg-danger">Breaking</span>**Consolidated native and custom form elements.** Checkboxes, radios, selects, and other inputs that had native and custom classes in v4 have been consolidated. Now nearly all our form elements are entirely custom, most without the need for custom HTML.
-<spanclass="badge bg-danger">Breaking</span> Dropped `.input-group-append` and `.input-group-prepend`. You can now just add buttons and `.input-group-text` as direct children of the input groups.
- The longstanding [Missing border radius on input group with validation feedback bug](https://github.com/twbs/bootstrap/issues/25110) is finally fixed by adding an additional `.has-validation` class to input groups with validation.
-<spanclass="badge bg-danger">Breaking</span>**Dropped form-specific layout classes for our grid system.** Use our grid and utilities instead of `.form-group`, `.form-row`, or `.form-inline`.
-<spanclass="badge bg-danger">Breaking</span>`.form-text` no longer sets `display`, allowing you to create inline or block help text as you wish just by changing the HTML element.
- Form controls no longer used fixed `height` when possible, instead deferring to `min-height` to improve customization and compatibility with other components.
- Unified `padding` values for alerts, breadcrumbs, cards, dropdowns, list groups, modals, popovers, and tooltips to be based on our `$spacer` variable. [See #30564](https://github.com/twbs/bootstrap/pull/30564).
-<spanclass="badge bg-danger">Breaking</span> Dropped all `.badge-*` color classes for background utilities (e.g., use `.bg-primary` instead of `.badge-primary`).
-<spanclass="badge bg-danger">Breaking</span>**[Toggle buttons]({{< docsref "/forms/checks-radios#toggle-buttons" >}}), with checkboxes or radios, no longer require JavaScript and have new markup.** We no longer require a wrapping element, add `.btn-check` to the `<input>`, and pair it with any `.btn` classes on the `<label>`. [See #30650](https://github.com/twbs/bootstrap/pull/30650). _The docs for this has moved from our Buttons page to the new Forms section._
-<spanclass="badge bg-danger">Breaking</span>**Dropped `.btn-block` for utilities.** Instead of using `.btn-block` on the `.btn`, wrap your buttons with `.d-grid` and a `.gap-*` utility to space them as needed. Switch to responsive classes for even more control over them. [Read the docs for some examples.]({{< docsref "/components/buttons#block-buttons" >}})
-<spanclass="badge bg-danger">Breaking</span> Dropped `.card-deck` in favor of our grid. Wrap your cards in column classes and add a parent `.row-cols-*` container to recreate card decks (but with more control over responsive alignment).
-<spanclass="badge bg-danger">Breaking</span> Replaced the `.card` based accordion with a [new Accordion component]({{< docsref "/components/accordion" >}}).
- Added new [`.carousel-dark` variant]({{< docsref "/components/carousel#dark-variant" >}}) for dark text, controls, and indicators (great for lighter backgrounds).
- Close buttons now use a `background-image` (embedded SVG) instead of a `×` in the HTML, allowing for easier customization without the need to touch your markup.
-<spanclass="badge bg-danger">Breaking</span> All the events for the dropdown are now triggered on the dropdown toggle button and then bubbled up to the parent element.
- Dropdown menus now have a `data-bs-popper="static"` attribute set when the positioning of the dropdown is static, or dropdown is in the navbar. This is added by our JavaScript and helps us use custom position styles without interfering with Popper's positioning.
-<spanclass="badge bg-danger">Breaking</span> Dropped `flip` option for dropdown plugin in favor of native Popper configuration. You can now disable the flipping behavior by passing an empty array for [`fallbackPlacements`](https://popper.js.org/docs/v2/modifiers/flip/#fallbackplacements) option in [flip](https://popper.js.org/docs/v2/modifiers/flip/) modifier.
- Dropdown menus can now be clickable with a new `autoClose` option to handle the [auto close behavior]({{< docsref "/components/dropdowns#auto-close-behavior" >}}). You can use this option to accept the click inside or outside the dropdown menu to make it interactive.
-<spanclass="badge bg-danger">Breaking</span> Dropped the jumbotron component as it can be replicated with utilities. [See our new Jumbotron example for a demo.]({{< docsref "/examples/jumbotron" >}})
- Toasts can now be [positioned]({{< docsref "/components/toasts#placement" >}}) in a `.toast-container` with the help of [positioning utilities]({{< docsref "/utilities/position" >}}).
-<spanclass="badge bg-danger">Breaking</span> The default value for the `fallbackPlacements` is changed to `['top', 'right', 'bottom', 'left']` for better placement of popper elements.
-<spanclass="badge bg-danger">Breaking</span> Renamed several utilities to use logical property names instead of directional names with the addition of RTL support:
- Added new [position utilities]({{< docsref "/utilities/position#arrange-elements" >}}) for `top`, `right`, `bottom`, and `left`. Values include `0`, `50%`, and `100%` for each property.
- Added `.fs-*` utilities for `font-size` utilities (with RFS enabled). These use the same scale as HTML's default headings (1-6, large to small), and can be modified via Sass map.
-<spanclass="badge bg-danger">Breaking</span> Removed `.rounded-sm` and `rounded-lg`, and introduced a new scale of classes, `.rounded-0` to `.rounded-3`. [See #31687](https://github.com/twbs/bootstrap/pull/31687).
-<spanclass="badge bg-danger">Breaking</span>**Responsive embed helpers have been renamed to [ratio helpers]({{< docsref "/helpers/ratio" >}})** with new class names and improved behaviors, as well as a helpful CSS variable.
- Classes have been renamed to change `by` to `x` in the aspect ratio. For example, `.ratio-16by9` is now `.ratio-16x9`.
- We've dropped the `.embed-responsive-item` and element group selector in favor of a simpler `.ratio > *` selector. No more class is needed, and the ratio helper now works with any HTML element.
- The `$embed-responsive-aspect-ratios` Sass map has been renamed to `$aspect-ratios` and its values have been simplified to include the class name and the percentage as the `key: value` pair.
- CSS variables are now generated and included for each value in the Sass map. Modify the `--bs-aspect-ratio` variable on the `.ratio` to create any [custom aspect ratio]({{< docsref "/helpers/ratio#custom-ratios" >}}).
-<spanclass="badge bg-danger">Breaking</span> Data attributes for all JavaScript plugins are now namespaced to help distinguish Bootstrap functionality from third parties and your own code. For example, we use `data-bs-toggle` instead of `data-toggle`.
- **All plugins can now accept a CSS selector as the first argument.** You can either pass a DOM element or any valid CSS selector to create a new instance of the plugin:
```js
var modal = new bootstrap.Modal('#myModal')
var dropdown = new bootstrap.Dropdown('[data-bs-toggle="dropdown"]')
```
-`popperConfig` can be passed as a function that accepts the Bootstrap's default Popper config as an argument, so that you can merge this default configuration in your way. **Applies to dropdowns, popovers, and tooltips.**
- The default value for the `fallbackPlacements` is changed to `['top', 'right', 'bottom', 'left']` for better placement of Popper elements. **Applies to dropdowns, popovers, and tooltips.**
- Removed underscore from public static methods like `_getInstance()` → `getInstance()`.
