More Split Views by KHROTU

More Split Views enhances Firefox's native Split View functionality by allowing you to arrange up to 4 tabs in a single window using customizable grid layouts.

Features

• Multi-Pane Layouts: Go beyond the default 2-pane split. Choose from 7 built-in layouts or create your own in the editor.
• Custom Layout Editor: Create your own pane arrangements using the visual editor.
• Flexible Modes: Apply splits directly in the current tab (using iframes) or open each pane as a separate popup window tiled to match your layout.

How it works

Since the WebExtensions API does not yet support creating native split views programmatically, this add-on builds a split view inside a single tab using CSS Grid and iframes. For the "Open as windows" mode, it uses windows.create() to create, resize, and relocate popup windows.

Limitations

• Websites that block embedding via X-Frame-Options or CSP frame-ancestors cannot be displayed in iframe mode. Use "Open as windows" for these sites.
• Built-in pages like about:newtab do not support content scripts; apply the split view from a standard webpage.