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This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The validity read-only property of the HTMLFieldSetElement interface returns a ValidityState object that represents the validity states this element is in. Although <fieldset> elements are never candidates for constraint validation, the validity state may still be invalid if a custom validity message has been set.
A ValidityState object.
The following example demonstrates that a <fieldset> is in an invalid state when a customError is set; in this state, checkValidity() returns true while the validityState's validity property is false.
Note: The :valid and :invalid CSS pseudo-classes are applied to <fieldset> elements based on the validity of its descendant form controls, not the fieldset itself.
| HTML # the-constraint-validation-api:dom-cva-validity |
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This page was last modified on Apr 10, 2025 by MDN contributors.
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