index.md

title	slug	page-type	browser-compat
HTML attribute: maxlength	Web/HTML/Attributes/maxlength	html-attribute	html.elements.input.maxlength html.elements.textarea.maxlength

{{HTMLSidebar}}

The maxlength attribute defines the maximum string length that the user can enter into an {{htmlelement('input')}} or {{htmlelement('textarea')}}. The attribute must have an integer value of 0 or higher.

The length is measured in UTF-16 code units, which (for most scripts) is equivalent to the number of characters. If no maxlength is specified, or an invalid value is specified, the input has no maximum length.

Any maxlength value must be greater than or equal to the value of minlength, if present and valid. The input will fail constraint validation if the length of the text value of the field is greater than maxlength UTF-16 code units long. Constraint validation is only applied when the value is changed by the user.

Constraint validation

While the browser will generally prevent user from entering more text than the maxlength attribute allows, should the length be longer than the maxlength allows, the read-only {{domxref("ValidityState.tooLong", "tooLong")}} property of a {{domxref("ValidityState")}} object will be true.

{{EmbedInteractiveExample("pages/tabbed/attribute-maxlength.html", "tabbed-shorter")}}

Examples

<input type="password" maxlength="4" />

{{EmbedLiveSample('Examples', '100%', 200)}}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• minlength
• size
• pattern
• Constraint validation
• Form validation
• {{htmlelement('input')}}