HTMLInputElement: minLength property

{{ApiRef("HTML DOM")}}

The minLength property of the {{domxref("HTMLInputElement")}} interface indicates the minimum number of characters (in {{glossary("UTF-16", "UTF-16 code units")}}) required for the value of the {{HTMLElement("input")}} element to be valid. It reflects the element's minlength attribute. -1 means there is no minimum length requirement.

[!NOTE] If the input has a value, and that value has fewer characters than the minlength attribute requires, the element is considered invalid and the {{domxref("ValidityState")}} object's {{domxref("ValidityState.tooShort", "tooShort")}} property will be true.

Value

A number representing the element's minlength if present or -1.

Example

Given the following HTML:

<p>
  <label for="password">Your password</label>
  <input id="password" type="password" minlength="8" maxlength="20" />
</p>

You can use the minLength property to retrieve or set the <input>'s minlength attribute value:

const inputElement = document.querySelector("#password");
console.log(`Element's minLength: ${inputElement.minLength}`); // "Element's minlength: 8"
inputElement.minLength = 12; // updates the element's minlength attribute value

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("HTMLInputElement.value")}}
• {{domxref("HTMLInputElement.maxLength")}}
• {{domxref("ValidityState.tooShort")}}