HTML attribute: minlength
Theminlength attribute defines the minimumstring length that the user can enter into an<input> or<textarea>. The attribute must have an integer value of 0 or higher.
The length is measured inUTF-16 code units, which is often but not always equal to the number of characters. If nominlength is specified, or an invalid value is specified, the input has no minimum length. This value must be less than or equal to the value ofmaxlength, otherwise the value will never be valid, as it is impossible to meet both criteria.
The input will fail constraint validation if the length of the text value of the field is less than minlength UTF-16 code units long, withvalidityState.tooShort returningtrue. Constraint validation is only applied when the value is changed by the user. Once submission fails, some browsers will display an error message indicating the minimum length required and the current length.
minlength does not implyrequired; an input only violates aminlength constraint if the user has input a value. If an input is notrequired, an empty string can be submitted even ifminlength is set.
Try it
<label for="name">Product name:</label><input name="name" type="text" value="Shampoo" minlength="3" maxlength="20" required /><label for="description">Product description:</label><textarea name="description" minlength="10" maxlength="40" required></textarea>label { display: block; margin-top: 1em;}input:valid,textarea:valid { background-color: palegreen;}Examples
By addingminlength="5", the value must either be empty or five characters or longer to be valid.
<label for="fruit">Enter a fruit name that is at least 5 letters long</label><input type="text" minlength="5" />We can use pseudoclasses to style the element based on whether the value is valid. The value will be valid as long as it is either null (empty) or five or more characters long.Lime is invalid,lemon is valid.
input { border: 2px solid currentcolor;}input:invalid { border: 2px dashed red;}input:invalid:focus { background-image: linear-gradient(pink, lightgreen);}Specifications
| Specification |
|---|
| HTML # attr-input-minlength |
| HTML # attr-textarea-minlength |