If you're on an iOS 14+ device and have Firefox 28.2 or higher, you can set Firefox as your default browser. By making Firefox your default, any links you click on in other apps will automatically open in Firefox, a browser that respects your privacy. Even if you have lots of links open, Firefox's easy-to-manage tabs makes browsing a breeze.

Older versions of Firefox: On older versions, you cannot change the default browser but you can send pages from Safari to Firefox.

Set Firefox as default browser (requires iOS 14)

To set Firefox as the default browser on your iOS device, you must must have iOS 14 (or higher) and Firefox for iOS version 28.2 (or higher).

If you see a display card, tap Go to Settings. Alternatively, you can open the Settings, then scroll down and tap Firefox.
Tap Default Browser App.
Choose Firefox from the list.

Older versions of iOS

If you're on an older version of iOS (pre-14), Apple does not allow changing the default browser on older versions but you can try the following workaround:

Send pages from Safari to Firefox

From Safari, tap the share icon at the bottom of the screen to bring up the share menu. (Note: You can also long-press on a link on a page to bring up the share menu.)
Choose Firefox as the destination in the share menu.
If Firefox is not listed in the options, tap the More button in the first row of the share menu.
Tap the switch next to Firefox to enable it.