devdocs/html/attributes%2Fmaxlength.html


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<header><h1>HTML attribute: maxlength</h1></header><div class="section-content">
<p>The <code>maxlength</code> attribute defines the maximum <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length">string length</a> that the user can enter into an <a href="../element/input"><code>&lt;input&gt;</code></a> or <a href="../element/textarea"><code>&lt;textarea&gt;</code></a>. The attribute must have an integer value of 0 or higher.</p> <p>The length is measured in UTF-16 code units, which (<a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length#strings_with_length_not_equal_to_the_number_of_characters">for most scripts</a>) is equivalent to the number of characters. If no <code>maxlength</code> is specified, or an invalid value is specified, the input has no maximum length.</p> <p>Any <code>maxlength</code> value must be greater than or equal to the value of <a href="minlength"><code>minlength</code></a>, 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.</p>
</div>
<h3 id="constraint_validation">Constraint validation</h3>
<div class="section-content"><p>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 <a href="https://developer.mozilla.org/en-US/docs/Web/API/ValidityState/tooLong"><code>tooLong</code></a> property of a <a href="https://developer.mozilla.org/en-US/docs/Web/API/ValidityState"><code>ValidityState</code></a> object will be true.</p></div>
<h2 id="try_it">Try it</h2>
<div class="section-content"><iframe class="interactive is-tabbed-shorter-height" height="200" src="https://interactive-examples.mdn.mozilla.net/pages/tabbed/attribute-maxlength.html" title="MDN Web Docs Interactive Example" loading="lazy"></iframe></div>
<h2 id="examples">Examples</h2>
<div class="section-content">
<div class="code-example">
<p class="example-header"><span class="language-name">html</span></p>
<pre data-signature="6ccbeNUrp6Dm4PAnSJPQTwdGLtQXwnKcSrq67FxHF88=" data-language="html"><span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>input</span> <span class="token attr-name">type</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>password<span class="token punctuation">"</span></span> <span class="token attr-name">maxlength</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>4<span class="token punctuation">"</span></span> <span class="token punctuation">/&gt;</span></span>
</pre>
</div>
<div class="code-example" id="sect1">

<iframe class="sample-code-frame" title="Examples sample" id="frame_examples" width="100%" height="200" src="https://live.mdnplay.dev/en-US/docs/Web/HTML/Attributes/maxlength/runner.html?id=examples" loading="lazy"></iframe>
</div>
</div>
<h2 id="specifications">Specifications</h2>
<div class="_table"><table class="standard-table">
<thead><tr><th scope="col">Specification</th></tr></thead>
<tbody><tr><td><a href="https://html.spec.whatwg.org/multipage/input.html#the-maxlength-and-minlength-attributes">HTML Standard <br><small># the-maxlength-and-minlength-attributes</small></a></td></tr></tbody>
</table></div>
<h2 id="browser_compatibility">Browser compatibility</h2>
<div class="_table"><table>
<thead>
<tr id="bct-browser-type">
<th></th>
<th colspan="6">Desktop</th>
<th colspan="6">Mobile</th>
</tr>
<tr id="bct-browsers">
<th></th>
<th>Chrome</th>
<th>Edge</th>
<th>Firefox</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
<th>WebView Android</th>
<th>Chrome Android</th>
<th>Firefox for Android</th>
<th>Opera Android</th>
<th>Safari on IOS</th>
<th>Samsung Internet</th>
</tr>
</thead>
<tbody><tr>
<th><code>maxlength</code></th>
<td class="bc-supports-yes">4</td>
<td class="bc-supports-yes">12</td>
<td class="bc-supports-yes">4</td>
<td class="bc-supports-yes">10</td>
<td class="bc-supports-yes">≤12.1</td>
<td class="bc-supports-yes">5</td>
<td class="bc-supports-yes">≤37</td>
<td class="bc-supports-yes">18</td>
<td class="bc-supports-yes">4</td>
<td class="bc-supports-yes">≤12.1</td>
<td class="bc-supports-yes">5</td>
<td class="bc-supports-yes">1.0</td>
</tr></tbody>
</table></div>
<div class="_table"><table>
<thead>
<tr id="bct-browser-type">
<th></th>
<th colspan="6">Desktop</th>
<th colspan="6">Mobile</th>
</tr>
<tr id="bct-browsers">
<th></th>
<th>Chrome</th>
<th>Edge</th>
<th>Firefox</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari</th>
<th>WebView Android</th>
<th>Chrome Android</th>
<th>Firefox for Android</th>
<th>Opera Android</th>
<th>Safari on IOS</th>
<th>Samsung Internet</th>
</tr>
</thead>
<tbody><tr>
<th><code>maxlength</code></th>
<td class="bc-supports-yes">1</td>
<td class="bc-supports-yes">12</td>
<td class="bc-supports-yes">1</td>
<td class="bc-supports-yes">5.5</td>
<td class="bc-supports-yes">≤12.1</td>
<td class="bc-supports-yes">1</td>
<td class="bc-supports-yes">4.4</td>
<td class="bc-supports-yes">18</td>
<td class="bc-supports-yes">4</td>
<td class="bc-supports-yes">≤12.1</td>
<td class="bc-supports-yes">1</td>
<td class="bc-supports-yes">1.0</td>
</tr></tbody>
</table></div>
<h3 id="html.elements.input.maxlength">html.elements.input.maxlength</h3>
<p>BCD tables only load in the browser<noscript> with JavaScript enabled. Enable JavaScript to view data.</noscript></p>
<h3 id="html.elements.textarea.maxlength">html.elements.textarea.maxlength</h3>
<p>BCD tables only load in the browser<noscript> with JavaScript enabled. Enable JavaScript to view data.</noscript></p>
<h2 id="see_also">See also</h2>
<div class="section-content"><ul> <li><a href="minlength"><code>minlength</code></a></li> <li><a href="size"><code>size</code></a></li> <li><a href="pattern"><code>pattern</code></a></li> <li><a href="../constraint_validation">Constraint validation</a></li> <li><a href="https://developer.mozilla.org/en-US/docs/Learn/Forms/Form_validation">Form validation</a></li> <li><a href="../element/input"><code>&lt;input&gt;</code></a></li> </ul></div><div class="_attribution">
  <p class="_attribution-p">
    &copy; 2005&ndash;2023 MDN contributors.<br>Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.<br>
    <a href="https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/maxlength" class="_attribution-link">https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/maxlength</a>
  </p>
</div>