Firefox Developer Edition 134 Free Download May 2026

If you are still using Chrome DevTools out of habit, give version 134 a spin for a week. Your console logs will thank you.

Version 134 introduces color-coded overlay toggles directly in the markup view. You can now toggle individual grid lines on/off without digging through the layout panel. Huge time saver for layout debugging. Firefox Developer Edition 134 Free Download

Have you spotted a bug in v134? Let the community know in the comments below! If you are still using Chrome DevTools out

Mozilla has updated the Compatibility panel to flag more modern CSS features (like @container queries and :has() selectors) that might break in older Safari or Chrome versions. Why Use the Developer Edition over Regular Firefox? You might be thinking, “Can’t I just use standard Firefox?” You can now toggle individual grid lines on/off

Supercharge Your Workflow: Download Firefox Developer Edition 134 (Free)