Firefox 149 Split View: Put Two Tabs Side by Side

Firefox Split View is useful when a task depends on two pages that you need to see together. Instead of repeatedly switching tabs or arranging two browser windows, you can pair the relevant tabs inside one Firefox window. Mozilla introduced the feature in Firefox 149. Independent coverage from UbuntuHandbook describes the resulting side-by-side layout.

This guide is based on current documentation and source review. It does not report product testing.

Scope

Platform: Firefox Desktop

Version: Firefox 149 or later

Task: Create, resize, check, and manage a Split View containing two tabs. The Firefox 149 release notes describe the feature as showing two pages side by side in one window.

Prerequisites

Open Firefox Desktop and confirm that its version is 149 or later. Prepare the two pages that belong to the same task. Good pairs include a source and a writing surface, a timetable and a booking page, or two product pages whose details you want to compare.

Choose a pair with a clear relationship. Split View reduces tab switching, but it does not make an unfocused collection of pages easier to understand. If you need several unrelated pages at once, separate windows or tab groups may remain clearer.

Procedure

1. Open the first page in a normal tab.
2. Right-click that tab and choose Add Split View. The documented alternative is to select two tabs, right-click, and choose Open in Split View, as explained by the Mozilla Split View introduction.
3. If you began with one tab, select the second page from the available tabs shown in the other pane. Keep the reference page on one side and the page receiving your input on the other. That stable arrangement makes it easier to remember which pane has which role.
4. Adjust the layout by dragging the vertical divider. OMG! Ubuntu’s Firefox 149 coverage notes that dragging the middle handle resizes the split. Give more width to the page with dense tables, long form fields, or wide documents.
5. Work through the task without opening extra pages into the pair. When a link would replace information you still need, open it in another tab instead. This is a workflow recommendation, not a product restriction.

For research and writing, a useful default is evidence on the left and notes on the right. For a purchase comparison, preserve the same attribute order on both pages: price, included features, restrictions, and cancellation terms. The browser supplies the layout; you still need a consistent comparison method.

Verification and expected outcome

Check that both chosen pages are visible inside one Firefox window. Drag the divider slightly in each direction and confirm that the pane widths change. Confirm that the page you need to read remains visible while you interact with the other pane.

Expected outcome: two related tabs appear side by side in one Firefox window, and the vertical divider changes how much width each page receives.

If the result feels cramped, maximize the window, reduce page zoom cautiously, or return to separate windows. Split View is most effective when the task genuinely benefits from simultaneous reference, not simply because two pages happen to be open.

Managing or leaving the view

The pane menu provides management choices including Separate Tabs, Reverse Tabs, and Close Both Tabs, according to The Register’s Firefox 149 coverage. Use Reverse Tabs when the working page is on the less convenient side. Use Separate Tabs when the paired layout is no longer helping but both pages should remain open. Reserve Close Both Tabs for a completed task after checking for unsaved form or editor content.

The broader lesson is to pair pages by task, not by topic alone. A documentation page and the configuration screen it explains form a useful pair; two long articles competing for the same narrow pane may not. Readers organizing other desktop workflows may also find the PowerToys workflow guide useful. Those evaluating a different desktop application boundary can consult the Thunderbird Exchange guide.