Developer
Firefox Developer Edition · legacy macOS compatibility
Firefox build with developer tools and early platform features.
Current evidence confirms OS coverage only, not a precise final compatible version or lifecycle cutoff. This page stays out of search indexing until stronger legacy-version evidence is added.
Choose macOS manually when detection is unavailable.
| macOS | Version or support record | Download |
|---|---|---|
| Record for this systemmacOS Catalina 10.15 | Releases listed by source (final version unconfirmed) ● OS coverage record | |
| Record for this systemmacOS Big Sur 11 | Releases listed by source (final version unconfirmed) ● OS coverage record | |
| Record for this systemmacOS Monterey 12 | Releases listed by source (final version unconfirmed) ● OS coverage record | |
| Record for this systemmacOS Ventura 13 | Releases listed by source (final version unconfirmed) ● OS coverage record |
Sources & verification
● Last checked 2026-09-16
Firefox Developer Edition ↗
macOS Catalina 10.15 · macOS Big Sur 11 · macOS Monterey 12 · macOS Ventura 13
Compatibility notes
macOS Catalina 10.15 · macOS Big Sur 11 · macOS Monterey 12 · macOS Ventura 13
Firefox Developer Edition is not supported on macOS 10.14 and older, so Catalina is the oldest tracked supported release.