Bug: Uncontrolled <input /> element has value attribute removed

[imjordanxd]

React version: React 19

Steps To Reproduce

1. Pass an value={undefined} as a prop to an <input /> element
2. Observe the DOM and see the value attribute is absent

Link to code example:

React 18

React 19

The current behavior

React 18 passed a booleanish attribute i.e. <input value />. React 19 omitted the attribute altogether i.e. <input />. This is causing a lot of failures in our snapshot tests. I'm not sure if this behaviour is expected in React 19 and I can't find anything in the release notes apart from this loosely related PR. If this behaviour is expected in 19, it would be great to mention that somewhere!

[narekmalk]

Can I take this issue?

[ronak-create]

Use defaultValue Instead of value

If you're dealing with uncontrolled inputs:

<input defaultValue={someValue} />

• defaultValue does suffer from the undefined issue in React 19.
• Useful for forms where React doesn't need to control the value.

[codeAdityagithub]

It is expected behaviour, as falsy values for attributes won't parse those values and thus not appear on the dom.