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FAQs

Frequently Asked Questions

Stuck on a particular problem? Check some of these common gotchas first in our FAQ.

If you still can't find what you're looking for, you can ask the community in Spectrum. For how-to questions and other non-issues, please use StackOverflow instead of Github issues. There is a StackOverflow tag called material-ui that you can use to tag your questions.

Why aren't my components rendering correctly in production builds?

This is likely an n°1 issue that happens due to class name conflicts once your code is in a production bundle. For Material-UI to work, the className values of all components on a page must be generated by a single instance of the class name generator.

To correct this issue, all components on the page need to be initialized such that there is only ever one class name generator between them.

You could end up accidentally using two class name generators in a variety of scenarios:

  • You accidentally bundle two versions of Material-UI. You might have a dependency not correctly setting Material-UI as a peer dependency.
  • You are using StylesProvider for a subset of your React Tree.
  • You are using a bundler and it is splitting code in a way that causes multiple class name generator instances to be created.

If you are using webpack with the SplitChunksPlugin, try configuring the runtimeChunk setting under optimizations.

Overall, it's simple to recover from this problem by wrapping each Material-UI application with StylesProvider components at the top of their component trees and using a single class name generator shared between them.

Why do the fixed positioned elements move when a modal is opened?

We block the scroll as soon as a modal is opened. This prevents interacting with the background when the modal should be the only interactive content, however, removing the scrollbar can make your fixed positioned elements move. In this situation, you can apply a global .mui-fixed class name to tell Material-UI to handle those elements.

How can I disable the ripple effect globally?

The ripple effect is exclusively coming from the BaseButton component. You can disable the ripple effect globally by providing the following in your theme:

import { createMuiTheme } from '@material-ui/core';

const theme = createMuiTheme({
  props: {
    // Name of the component ⚛️
    MuiButtonBase: {
      // The properties to apply
      disableRipple: true, // No more ripple, on the whole application 💣!
    },
  },
});

How can I disable transitions globally?

You can disable transitions globally by providing the following in your theme:

import { createMuiTheme } from '@material-ui/core';

const theme = createMuiTheme({
  transitions: {
    // So we have `transition: none;` everywhere
    create: () => 'none',
  },
});

Sometimes you will want to enable this behavior conditionally, for instance during testing or on low-end devices, in these cases, you can dynamically change the theme value.

You can go one step further by disabling all the transitions, animations and the ripple effect:

import { createMuiTheme } from '@material-ui/core';

const theme = createMuiTheme({
  transitions: {
    // So we have `transition: none;` everywhere
    create: () => 'none',
  },
  overrides: {
    // Name of the component ⚛️
    CssBasline: {
      // Name of the rule
      '@global': {
        '*, *::before, *::after': {
          transition: 'none !important',
          animation: 'none !important',
        },
      },
    },
  },
  props: {
    // Name of the component ⚛️
    MuiButtonBase: {
      // The properties to apply
      disableRipple: true, // No more ripple, on the whole application!
    },
  },
});

Do I have to use JSS to style my app?

It's recommended:

  • It comes built in, so carries no additional bundle size overhead.
  • It's fast & memory efficient.
  • It has a clean, consistent API.
  • It supports a number of advanced features, either natively, or through plugins.

However perhaps you're adding some Material-UI components to an app that already uses another styling solution, or are already familiar with a different API, and don't want to learn a new one? In that case, head over to the Style Library Interoperability section, where we show how simple it is to restyle Material-UI components with alternative style libraries.

When should I use inline-style vs CSS?

As a rule of thumb, only use inline-style for dynamic style properties. The CSS alternative provides more advantages, such as:

  • auto-prefixing
  • better debugging
  • media queries
  • keyframes

How do I use react-router?

We have documented how to use a third-party routing library with the ButtonBase component. A lot of our interactive components use it internally: Link, Button, MenuItem, <ListItem button />, Tab, etc. You can use the same solution with them.

How can I access the DOM element?

All Material-UI components that should render something in the DOM forward their ref to the underlying DOM component. This means that you can get DOM elements by reading the ref attached to Material-UI components:

// or a ref setter function
const ref = React.createRef();
// render
<Button ref={ref} />;
// usage
const element = ref.current;

If you're not sure if the Material-UI component in question forwards its ref you can check the API documentation under "Props" e.g. the [/api/button/#props](Button API) includes

The ref is forwarded to the root element.

indicating that you can access the DOM element with a ref.

I have several instances of styles on the page

If you are seeing a warning message in the console like the one below, you probably have several instances of @material-ui/styles initialized on the page.

It looks like there are several instances of @material-ui/styles initialized in this application. This may cause theme propagation issues, broken class names and makes your application bigger without a good reason.

Possible reasons

There are several common reasons for this to happen:

  • You have another @material-ui/styles library somewhere in your dependencies.
  • You have a monorepo structure for your project (e.g, lerna, yarn workspaces) and @material-ui/styles module is a dependency in more than one package (this one is more or less the same as the previous one).
  • You have several applications that are using @material-ui/styles running on the same page (e.g., several entry points in webpack are loaded on the same page).

Duplicated module in node_modules

If you think that the issue is in duplicated @material-ui/styles module somewhere in your dependencies, there are several ways to check this. You can use npm ls @material-ui/styles, yarn list @material-ui/styles or find -L ./node_modules | grep /@material-ui/styles/package.json commands in your application folder.

If none of these commands identified the duplication, try analyzing your bundle for multiple instances of @material-ui/styles. You can just check your bundle source, or use a tool like source-map-explorer or webpack-bundle-analyzer.

If you identified that duplication is the issue that you are encountering there are several things you can try to solve it:

If you are using npm you can try running npm dedupe. This command searches the local dependencies and tries to simplify the structure by moving common dependencies further up the tree.

If you are using webpack, you can change the way it will resolve the @material-ui/styles module. You can overwrite the default order in which webpack will look for your dependencies and make your application node_modules more prioritized than default node module resolution order:

  resolve: {
+   alias: {
+     "@material-ui/styles": path.resolve(appFolder, "node_modules", "@material-ui/styles"),
+   }
  }

Usage with Lerna

One possible fix to get @material-ui/styles to run in a Lerna monorepo across packages, is to hoist shared dependencies to the root of your monorepo file. Try running the bootstrap option with the --hoist flag.

lerna bootstrap --hoist

Alternatively, you can remove @material-ui/styles from your package.json file and hoist it manually to your top-level package.json file.

Example of a package.json file in a Lerna root folder

{
  "name": "my-monorepo",
  "devDependencies": {
    "lerna": "latest"
  },
  "dependencies": {
    "@material-ui/styles": "^4.0.0"
  },
  "scripts": {
    "bootstrap": "lerna bootstrap",
    "clean": "lerna clean",
    "start": "lerna run start",
    "build": "lerna run build"
  }
}

Running multiple applications on one page

If you have several applications running on one page, consider using one @material-ui/styles module for all of them. If you are using webpack, you can use CommonsChunkPlugin to create an explicit vendor chunk, that will contain the @material-ui/styles module:

  module.exports = {
    entry: {
+     vendor: ["@material-ui/styles"],
      app1: "./src/app.1.js",
      app2: "./src/app.2.js",
    },
    plugins: [
+     new webpack.optimize.CommonsChunkPlugin({
+       name: "vendor",
+       minChunks: Infinity,
+     }),
    ]
  }

My App doesn't render correctly on the server

If it doesn't work, in 99% of cases it's a configuration issue. A missing property, a wrong call order, or a missing component. We are very strict about configuration, and the best way to find out what's wrong is to compare your project to an already working setup, check out our reference implementations, bit by bit.

CSS works only on first load then is missing

The CSS is only generated on the first load of the page. Then, the CSS is missing on the server for consecutive requests.

Action to Take

We rely on a cache, the sheets manager, to only inject the CSS once per component type (if you use two buttons, you only need the CSS of the button one time). You need to create a new sheets instance for each request.

example of fix:

-// Create a sheets instance.
-const sheets = new ServerStyleSheets();

function handleRender(req, res) {
+ // Create a sheets instance.
+ const sheets = new ServerStyleSheets();

  //…

  // Render the component to a string.
  const html = ReactDOMServer.renderToString(

React class name hydration mismatch

There is a class name mismatch between the client and the server. It might work for the first request. Another symptom is that the styling changes between initial page load and the downloading of the client scripts.

Action to Take

The class names value relies on the concept of class name generator. The whole page needs to be rendered with a single generator. This generator needs to behave identically on the server and on the client. For instance:

  • You need to provide a new class name generator for each request. But you shouldn't share a createGenerateClassName() between different requests:

example of fix:

-// Create a new class name generator.
-const generateClassName = createGenerateClassName();

function handleRender(req, res) {
+ // Create a new class name generator.
+ const generateClassName = createGenerateClassName();

  //…

  // Render the component to a string.
  const html = ReactDOMServer.renderToString(
  • You need to verify that your client and server are running the exactly the same version of Material-UI. It is possible that a mismatch of even minor versions can cause styling problems. To check version numbers, run npm list @material-ui/core in the environment where you build your application and also in your deployment environment.

    You can also ensure the same version in different environments by specifying a specific MUI version in the dependencies of your package.json.

example of fix (package.json):

  "dependencies": {
    ...
-   "@material-ui/core": "^4.0.0",
+   "@material-ui/core": "4.0.0",
    ...
  },
  • You need to make sure that the server and the client share the same process.env.NODE_ENV value.

Why are the colors I am seeing different from what I see here?

The documentation site is using a custom theme. Hence, the color palette is different from the default theme that Material-UI ships. Please refer to this page to learn about theme customization.

Material-UI is awesome. How can I support the project?

There are many ways to support Material-UI:

If you use Material-UI in a commercial project and would like to support its continued development by becoming a Sponsor, or in a side or hobby project and would like to become a backer, you can do so through OpenCollective.

All funds raised are managed transparently, and Sponsors receive recognition in the README and on the Material-UI home page.

Why does component X require a DOM node in a prop instead of a ref object?

Components like the Portal or Popper require a DOM node in the container or anchorEl prop respectively. It seems convenient to simply pass a ref object in those props and let Material-UI access the current value. This works in a simple scenario:

function App() {
  const container = React.useRef(null);

  return (
    <div className="App">
      <Portal container={container}>
        <span>portaled children</span>
      </Portal>
      <div ref={container} />
    </div>
  );
}

where Portal would only mount the children into the container when container.current is available. Here is a naive implementation of Portal:

function Portal({ children, container }) {
  const [node, setNode] = React.useState(null);

  React.useEffect(() => {
    setNode(container.current);
  }, [container]);

  if (node === null) {
    return null;
  }
  return ReactDOM.createPortal(children, node);
}

With this simple heuristic Portal might re-render after it mounts because refs are up-to-date before any effects run. However, just because a ref is up-to-date doesn't mean it points to a defined instance. If the ref is attached to a ref forwarding component it is not clear when the DOM node will be available. In the above example the Portal would run run an effect once but might not re-render because ref.current is still null. This is especially apparent for React.lazy components in Suspense. The above implementation could also not account for a change in the DOM node.

This is why we require a prop with the actual DOM node so that React can take care of determining when the Portal should re-render:

function App() {
  const [container, setContainer] = React.useState(null);
  const handleRef = React.useCallback(instance => setContainer(instance), [setContainer])

  return (
    <div className="App">
      <Portal container={container}>
        <span>Portaled</span>
      </Portal>
      <div ref={handleRef} />
    </div>
  );
}