If you absolutely need legacy extensions, consider running or Basilisk instead – they offer similar old-extension support but with some ongoing security patches.
Here’s a review of , focusing on its relevance, strengths, and major drawbacks for today’s users. Overview Portable Firefox 52 (specifically 52.9.0 ESR) was released in 2018 as the final version of Firefox that supported legacy extensions (Classic add-ons like DownThemAll, Classic Theme Restorer, NoScript legacy, etc.) and the last to run on Windows XP and Vista. The “Portable” version comes from third-party launchers (e.g., PortableApps.com), allowing it to run from a USB drive without installation. What’s Good (Still Useful In 2024-2026) ✅ Legacy extension support You can still use powerful pre-WebExtension add-ons that were abandoned after Firefox 57 (Quantum). Great for niche workflows – e.g., old download managers, tab managers, or UI customizers. portable firefox 52
✅ No installation, leaves no registry traces, can be carried on a USB stick. Uses far less RAM than modern browsers (helpful on old hardware). If you absolutely need legacy extensions, consider running
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