Your Button component should default to type="button"

Published on in JavaScript, React and TypeScript

A <button> element defaults to type="submit" which can cause accidental form submissions. Make type="button" the default in your Button component to make your life easier.

Table of contents

type="button" vs type="submit"

A <button> element without a type attribute defaults to type="submit". Clicking a submit button associated with a <form> submits the form unless event.preventDefault() is called.

A <button> element with type="button" on the other hand does nothing by default when clicked. Calling event.preventDefault() does nothing because there's no default action to prevent.

Setting your Button component to default to type="button" allows you to not worry about:

  • accidental form submissions
  • having to remember call event.preventDefault().

Also, using <Button type="submit"> makes it explicit that it's a submit button.

Example with React and TypeScript

type Props = React.ButtonHTMLAttributes<HTMLButtonElement> & { type?: 'submit' }

const Button = ({ children, type, ...props }: Props) => (
  <button {...props} type={type || 'button'}>

// Usage:

<Button /> // Defaults to `type="button"`
<Button type="submit" />

The type prop's value in React.ButtonHTMLAttributes<HTMLButtonElement> is "submit" | "button" | "reset" | undefined. I'm restricting the value to "submit" | undefined, so that only type="submit" is allowed. (Omitting the prop is also allowed.)

  • type="button" is not allowed because it's the default, so it would be unnecessary noise.
  • type="reset" is not allowed because reset buttons (i.e. buttons that empty the whole form) are so stupid. 🤡 Not on my watch!