Your default browser is the one that opens links from email, documents, messages, PDFs, and other apps. If links keep opening in Chrome, Edge, or Safari and you want Firefox instead, set Firefox as default from Firefox itself or from the operating system settings.
Does this affect you?
Use this for Firefox on Windows 10, Windows 11, or macOS when external links open in another browser.
Set it from inside Firefox
This is the easiest method.
- Open Firefox.
- Click the three-line menu.
- Open Settings.
- Stay on the General panel.
- Find Default Browser near the top.
- Click Make Default.
- Approve any Windows or macOS confirmation prompt.
Set it through Windows or Mac settings
Use this if the Firefox button does not appear or does not stick.
On Windows:
- Open Start > Settings.
- Choose Apps > Default apps.
- Search for Firefox.
- Open the Firefox default apps page.
- Click Set default if available, or assign Firefox to web links and file types such as HTTP, HTTPS, .htm, and .html.
On Mac:
- Open Apple menu > System Settings.
- Choose General.
- Open Default web browser.
- Select Firefox from the dropdown.
More control
Check software that resets defaults
Some antivirus or PC manufacturer tools include browser protection that can restore another browser as default. Disable that feature, then set Firefox again.
Set PDFs separately
On Windows, PDFs and other file types can have separate default apps. If PDFs still open elsewhere, search for PDF in Default apps and choose Firefox or your preferred PDF reader.
Test from another app
Click a link in email, chat, or a document. If Firefox opens, the default browser change is working.
Sources
- Mozilla Support – Make Firefox your default browser (2025)
- Mozilla Support – Make Firefox your default browser on Windows (2025)
- Mozilla Support – Setting Firefox as the default browser does not work: what to do (2025)