HTML Code

<!DOCTYPE html>

<html lang=en>

<head>

  <meta charset=UTF-8>

  <meta name=viewport content="width=device-width,initial-scale=1">

  <title>oninput — character count</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 .75rem;font-size:1.25rem;color:#0f172a}label{display:block;font-size:.8125rem;font-weight:500;margin-bottom:.35rem}textarea{display:block;width:100%;max-width:360px;min-height:100px;padding:.5rem .75rem;border:1px solid #cbd5e1;border-radius:8px;font-size:.875rem;font-family:inherit;resize:vertical}#counter{margin-top:.5rem;font-size:.8125rem;color:#64748b}#counter.warn{color:#b45309}</style>

</head>

<body>

  <h1>Live character count</h1>

  <p>The counter updates on every keystroke and paste.</p>

  <label for=bio>Short bio</label>

  <textarea id=bio maxlength=200 placeholder="Tell us about yourself…"></textarea>

  <p id=counter aria-live=polite>200 characters remaining</p>



  <script>var bio=document.getElementById("bio"),counter=document.getElementById("counter"),max=200;bio.addEventListener("input",(function(){var e=max-bio.value.length;counter.textContent=e+" characters remaining",counter.className=e<=20?"warn":""}))</script>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

HTML oninput Attribute — Live character count