In the Safari app on your iPhone running iOS 15 you can now customize your start page, change your Safari layout, change the text size on websites, and change display and privacy settings. When signed into iCloud with the same Apple ID on multiple devices, tabs you have open, your bookmarks, history, and Reading List will remain up to date across all your devices.
Change your Safari layout
You can choose between the top Single Tab you’re used to and the new bottom Tab Bar layout.
Go to Settings > Safari, then scroll down to Tabs.
Select the Tab Bar or Single Tab layout option. You can move between layouts without losing the tabs that are open.
Customize your start page
When you open a new tab, you begin on your start page. You can customize your start page with new backgrounds and options.
Select to view all open windows, then tap the plus sign (+).
Scroll to the bottom of the page, then tap Edit.
Choose options for your start page.
Use Start Page on All Devices: Keep your preferences and settings updated across all your Apple devices where you’re signed in with your Apple ID.
Favorites: Display shortcuts to your favorite bookmarked websites.
Siri Suggestions: As you search, use Siri to suggest webpages.
Shared with You: See links shared with you in Messages, Mail, and more.
Frequently Visited: Go straight to the websites you visit most.
Privacy Report: Stay updated on how many trackers and websites Safari blocked from tracking you.
Reading List: List pages currently in your Reading List.
iCloud Tabs: Show open tabs from other Apple devices where you’re signed in with the same Apple ID and Safari is turned on in iCloud settings or preferences.
More Information: https://support.apple.com/guide/iphone/customize-your-safari-settings-iphb3100d149/ios