HTMLOutputElement: validationMessage property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨August 2016⁩.

The validationMessage read-only property of the HTMLOutputElement interface returns a string representing a localized message that describes the validation constraints that the <output> control does not satisfy (if any). This is the empty string as <output> elements are not candidates for constraint validation (HTMLOutputElement.willValidate is false).