Modal
The Modal component lets you create dialogs, popovers, lightboxes, and other elements that force the user to take action before continuing.
Introduction
Modal is a utility component that renders its children in front of a backdrop. This lets you create an element that your users must interact with before continuing in the parent application.
Modal is a lower-level construct that is used in the following Material UI components:
Component
import { Modal } from '@mui/base/Modal';
The following demo shows how to create and style a basic modal. Click Open modal to see how it behaves:
Transitions
You can animate the open and close states of a Modal using a transition component, as long as that component fulfills the following requirements:
- Is a direct child descendant of the Modal
- Has an
in
prop—this corresponds to the open/close state - Calls the
onEnter
callback prop when the enter transition starts - Calls the
onExited
callback prop when the exit transition is completed
Modal has built-in support for react-transition-group:
You can also use react-spring with Modal, but it will require additional custom configuration:
Performance
The Modal's content is unmounted when it's not open. This means that it will need to be re-mounted each time it's opened.
If you're rendering expensive component trees inside your Modal, and you want to optimize for interaction responsiveness, you can change this default behavior by enabling the keepMounted
prop.
You can also use the keepMounted
prop if you want to make the content of the Modal available to search engines (even when the Modal is closed).
The following demo shows how to apply this prop to keep the Modal mounted:
As with any performance optimization, the keepMounted
prop won't necessarily solve all of your problems.
Explore other possible bottlenecks in performance where you could make more considerable improvements before implementing this prop.
Server-side modal
React doesn't support the createPortal()
API on the server.
To display a Modal rendered on the server, you need to disable the portal feature with the disablePortal
prop, as shown in the following demo:
Server-side modal
If you disable JavaScript, you will still see me.Limitations
Overflow layout shift
The Modal disables the page scrolling while open by setting overflow: hidden
as inline-style on the relevant scroll container, this hides the scrollbar and hence impacts the page layout.
To compensate for this offset and avoid a layout shift, the Modal also set a padding property on the scroll container (~15px under normal conditions).
This can create a layout shift with position: fixed
and position: sticky
elements.
You need to add the .mui-fixed
class name on these elements so the Modal can add a CSS padding property when the scroll is disabled.
<Box sx={{ position: 'sticky', right: 0, top: 0, left: 0 }} className="mui-fixed">
Focus trap
Modal moves the focus back to the body of the component if the focus tries to escape it.
This is done for accessibility purposes, but it can potentially create issues for your users.
If the user needs to interact with another part of the page—for example, to interact with a chatbot window while a Modal is open in the parent app—you can disable the default behavior with the disableEnforceFocus
prop.
Hook
import useModal from '@mui/base/unstable_useModal';
The useModal
hook lets you apply the functionality of a Modal to a fully custom component.
It returns props to be placed on the custom component, along with fields representing the component's internal state.
Hooks do not support slot props, but they do support customization props.
The following demo shows how to build the same Modal as the one found in the Component section above, but with the useModal
hook:
If you use a ref to store a reference to the root element, pass it to the useModal
's ref
parameter, as shown in the demo above.
It will get merged with a ref used internally in the hook.
Accessibility
See the WAI-ARIA guide on the Dialog (Modal) pattern for complete details on accessibility best practices.
All interactive elements must have an accessible name. Use the
aria-labelledby="id..."
to give your Modal component an accessible name. You can also usearia-describedby="id..."
to provide a description of the Modal:<Modal aria-labelledby="modal-title" aria-describedby="modal-description"> <h2 id="modal-title">My Title</h2> <p id="modal-description">My Description</p> </Modal>
Follow the WAI-ARIA Authoring Practices to help you set the initial focus on the most relevant element based on the content of the Modal.