Making sure the domains listed in this article are allowed by your firewall or other software ensures that Firefox works correctly.

Update Service (Firefox and GMP)

• https://aus5.mozilla.org

Remote Settings

• https://firefox.settings.services.mozilla.com
• https://firefox-settings-attachments.cdn.mozilla.net
• https://content-signature-2.cdn.mozilla.net

Download locations for Firefox

• https://download.mozilla.org
• https://download.cdn.mozilla.net
• https://archive.mozilla.org
• https://ftp.mozilla.org

Telemetry

• https://incoming.telemetry.mozilla.org

Captive Portal Detection

• http://detectportal.firefox.com

Safe Browsing

• https://safebrowsing.googleapis.com

Mozilla accounts

• https://accounts.firefox.com
• https://profile.accounts.firefox.com/

Sync

• https://token.services.mozilla.com
• https://sync-1-us-west1-g.sync.services.mozilla.com

Tracking Protection

• https://tracking-protection.cdn.mozilla.net

Location Services

• https://location.services.mozilla.com

OpenH264 Video Codec Download

• http://ciscobinary.openh264.org

Widevine Content Decryption Module Download

• https://redirector.gvt1.com
• https://clients2.googleusercontent.com

DNS over HTTPS

• https://mozilla.cloudflare-dns.com
• https://dns.shaw.ca
• https://doh.xfinity.com
• https://firefox.dns.nextdns.io
• https://private.canadianshield.cira.ca

Extension Update

• https://addons.mozilla.org/
• https://versioncheck.addons.mozilla.org/

Extension Metadata for about:addons

• https://services.addons.mozilla.org/

New Tab Sponsored Tiles

• https://contile-images.services.mozilla.com

New Tab Sponsored Stories

• https://spocs.getpocket.com

New Tab Ads

• https://ads.mozilla.org

Firefox Suggest

• https://merino.services.mozilla.com