HTML Code

<!DOCTYPE html>
<html lang=en>
<head>
  <meta charset=UTF-8>
  <meta name=viewport content="width=device-width,initial-scale=1">
  <title>maxlength — form example</title>
  <style>body{font-family:system-ui,sans-serif;margin:0;padding:1.5rem;background:#f8fafc;color:#334155;line-height:1.7}h1{margin:0 0 1rem;font-size:1.25rem;color:#0f172a}label{display:block;margin:.75rem 0 .35rem;font-weight:500;font-size:.875rem}input,textarea{width:100%;max-width:320px;padding:.5rem .65rem;font:inherit;border:1px solid #cbd5e1;border-radius:6px}textarea{min-height:80px;resize:vertical}button{margin-top:1rem;padding:.5rem 1rem;font:inherit;cursor:pointer;border-radius:6px;border:1px solid #cbd5e1;background:#2563eb;color:#fff}.hint{margin-top:1rem;font-size:.8125rem;color:#64748b;max-width:420px}</style>
</head>
<body>
  <h1>maxlength on input and textarea</h1>
  <form onsubmit='event.preventDefault(),alert("Form demo — values within maxlength limits.")'>
    <label for=username>Username (max 20):</label>
    <input id=username name=username maxlength=20>

    <label for=message>Message (max 100):</label>
    <textarea id=message name=message maxlength=100></textarea>

    <button type=submit>Submit</button>

The browser stops you from typing past each maxlength limit.

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

HTML maxlength Attribute — Form with Textarea