Avoid for everyday browsing. Only keep a copy on a USB stick for very specific legacy tasks, and never enter passwords or personal data. For modern portable browsing, use Portable Firefox ESR 115 (still gets updates) or Portable Chrome .
✅ No installation, leaves no registry traces, can be carried on a USB stick. Uses far less RAM than modern browsers (helpful on old hardware). portable firefox 52
✅ You control exactly when/if to update – unlike modern Firefox or Chrome. Major Downsides (Critical for daily use) ❌ Severely outdated security Firefox 52 stopped receiving security updates in mid-2018. Over 6 years of known, unpatched vulnerabilities exist – including remote code execution, address bar spoofing, and JavaScript engine exploits. Do not use for banking, email, or any account logins on the modern web. Avoid for everyday browsing
If you absolutely need legacy extensions, consider running or Basilisk instead – they offer similar old-extension support but with some ongoing security patches. ✅ No installation, leaves no registry traces, can