How can I change the label size of a material ui TextField?

Question

I have a TextField defined as follows:

<TextField
  id="standard-with-placeholder"
  label="First Name"
  className={classes.textField}
  margin="normal"
/>

And it looks like this:

But I want it look like this:

The "First Name" text is larger. How can I adjust the label text size? Currently my styles object is empty. I think that should be where the CSS to do this should go, but I'm unsure what the css would look like for the label text.

Thanks

Answer 1

Here's an example of how to modify the label font size in v4 of Material-UI (v5 example further down). This example also modifies the font-size of the input on the assumption that you would want those sizes to be in sync, but you can play around with this in the sandbox to see the effects of changing one or the other.

import React from "react";
import ReactDOM from "react-dom";

import TextField from "@material-ui/core/TextField";
import { withStyles } from "@material-ui/core/styles";

const styles = {
  inputRoot: {
    fontSize: 30
  },
  labelRoot: {
    fontSize: 30,
    color: "red",
    "&$labelFocused": {
      color: "purple"
    }
  },
  labelFocused: {}
};
function App({ classes }) {
  return (
    <div className="App">
      <TextField
        id="standard-with-placeholder"
        label="First Name"
        InputProps={{ classes: { root: classes.inputRoot } }}
        InputLabelProps={{
          classes: {
            root: classes.labelRoot,
            focused: classes.labelFocused
          }
        }}
        margin="normal"
      />
    </div>
  );
}
const StyledApp = withStyles(styles)(App);
const rootElement = document.getElementById("root");
ReactDOM.render(<StyledApp />, rootElement);

Below is an equivalent example for v5 of Material-UI using styled instead of withStyles:

import React from "react";
import ReactDOM from "react-dom";

import MuiTextField from "@material-ui/core/TextField";
import { inputClasses } from "@material-ui/core/Input";
import { inputLabelClasses } from "@material-ui/core/InputLabel";
import { styled } from "@material-ui/core/styles";

const TextField = styled(MuiTextField)(`
  .${inputClasses.root} {
    font-size: 30px;
  }
  .${inputLabelClasses.root} {
    font-size: 30px;
    color: red;
    &.${inputLabelClasses.focused} {
      color: purple;
    }
  }
`);
function App() {
  return (
    <div className="App">
      <TextField
        id="standard-with-placeholder"
        label="First Name"
        margin="normal"
        variant="standard"
      />
    </div>
  );
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

Here are the relevant parts of the documentation:

• https://material-ui.com/api/text-field/
• https://material-ui.com/api/input/
• https://material-ui.com/api/input-label/
• https://material-ui.com/api/form-label/