1) Make Firefox your default browser (quick, system-wide) Windows 10 / 11 Open Settings (Windows key → Settings gear). Go to Apps → Default apps. Scroll to Web browser (or search “default apps”), click the current browser (likely Chrome). Choose Firefox from the list. macOS (Monterey / Ventura / later) Open System Settings or System Preferences. In System Settings: go to Desktop & Dock and find Default web browser. — In older macOS, open General in System Preferences and set Default web browser. Pick Firefox. Android Open Settings → Apps (or Apps & notifications). Tap Default apps → Browser app. Select Firefox. iPhone / iPad (iOS) Open Settings. Scroll down to Firefox (the app entry). Tap Default Browser App → choose Firefox. 2) Make Firefox the browser used by a specific app or website If an app or website has its own setting and it’s currently set to Chrome: Open that app or website’s Settings (often under profile → settings → preferences). Look for Default browser, Open links with, or Sign-in browser option. Change it from Chrome to System default or Firefox (if Firefox is listed). If it only shows Chrome and no other choice, use the steps below. 3) Quick manual workaround (always works) If a sign-in link keeps opening Chrome, do this: When the site shows the sign-in link, right-click the link → Copy link address (or copy the URL from the address bar). Open Firefox, paste the link into the address bar, and press Enter. This forces the sign-in to happen in Firefox. 4) If the site auto-opens Chrome even after you set defaults In Firefox: open the menu (three lines) → Settings → General → under Startup click Make Default…. Restart your device. Try the sign-in again (or paste the sign-in link into Firefox as in step 3). 5) Troubleshooting if sign-in fails in Firefox Pop-ups blocked? Firefox may block popups used by some sign-in flows. In Firefox: Menu → Settings → Privacy & Security → under Permissions uncheck or allow popups for the site. Cookies blocked? Sign-in often needs cookies. Settings → Privacy & Security → under Enhanced Tracking Protection set to Standard or allow cookies for that site. Extensions interfering? Try signing in with Private Window (Ctrl+Shift+P) or disable privacy extensions temporarily. Clear site data: click the padlock in the address bar → Clear cookies and site data for that site, then try again. Use copy/paste as in Step 3 if nothing else works. 6) Final quick checklist (do these in order) Set Firefox as system default (Step 1). Set Firefox as default inside Firefox (Step 4). Try signing in; if it still opens Chrome, copy the sign-in link and paste into Firefox (Step 3). If sign-in fails, check pop-ups, cookies, and extensions (Step 5).