You can turn off the Navigation Toolbar if you like. Either:

• right-click a blank area of the tab bar
• right-click the "+" button on the tab bar
• View menu > Toolbars

You also can change the display in the "new tab" page to a blank page if you like. There's a hidden setting for that.

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste newtab and pause while the list is filtered

(3) Double-click the browser.newtab.url preference and enter your preferred page:

• Page thumbnails (default) => about:newtab
• Blank tab => about:blank
• Built-in Firefox home page => about:home
• Any other page => full URL to the page

Press Ctrl+t to open a new tab and verify that it worked. Is that what you wanted?

Consider using "jumpstart". It give you access to your bookmarks, your thumnails and more. https://addons.mozilla.org/en-US/firefox/addon/new-tab-jumpstart/

today i check it,. and i used https://addons.mozilla.org/en-US/firefox/addon/hide-bookmarksbar/?src=userprofile very good for hide bookmark. and show bookmark when open new tabs :)

see my firefox use hide bookmark:

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