The read-only rangeUnderflow property of a ValidityState object indicates if the value of an <input>, after having been edited by the user, does not conform to the constraints set by the element's min attribute.
If the field is numeric in nature, including the date, month, week, time, datetime-local, number and range types and a min value is set, if the value don't doesn't conform to the constraints set by the min value, the rangeUnderflow property will be true.
Given the following:
<input type="number" min="20" max="40" step="2"/>if value < 20, rangeUnderflow will be true. When true, the element matches the :invalid and :out-of-range CSS pseudo-classes.
Specifications
| Specification | Status | Comment |
| HTML Living StandardThe definition of 'ValidityState.rangeUnderflow' in that specification. | Living Standard | |
| HTML 5.1The definition of 'ValidityState.rangeUnderflow' in that specification. | Recommendation | |
| HTML5The definition of 'ValidityState.rangeUnderflow' in that specification. | Recommendation |
Browser compatibility
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No compatibility data found. Please contribute data for "api.ValidityState.rangeUnderflow" (depth: 1) to the MDN compatibility data repository.
See also
ValidityState.rangeOverflow- Constraint validation
- Forms: Data form validation
stepattributemaxattribute
ValidityState.rangeUnderflow by Mozilla Contributors is licensed under CC-BY-SA 2.5.
