# Enhance multitasking extensions with the new Tabs Split View API

> Source: <https://developer.chrome.com/blog/split-view-api-extensions?hl=en>
> Published: 2026-09-16 07:00:00+00:00

Earlier this year in February 2026, Chrome 145 introduced the
[native Split View](https://blog.google/products-and-platforms/products/chrome/chrome-productivity-improvements/)
which provides users with the ability to view and manage tabs side-by-side
within the same window, removing the need to rely on third-party tools to manage
separate OS windows. While users can manually add and remove tabs from a split
view through browser controls, it was not possible for developers to
programmatically control these new tabs layouts in Chrome extensions.

We're excited to announce the new Split View API, available starting in Chrome 155! Developed in close collaboration with Mozilla and other browser vendors in the WebExtensions Community Group, this new API allows extensions to detect, create, and manage built-in split views.

## Demo

## How it works

Previously, extensions building side-by-side experiences relied on brittle
workarounds like resizing multiple native windows, embedding pages in `<iframe>`
elements, or using side panels. Now, the new Split View API integrates directly
with Chrome's [Tabs
API](https://developer.chrome.com/docs/extensions/reference/api/tabs) to unlock
new tabs layout management capabilities.

### Manifest permissions

The Split View API is part of the `browser.tabs` namespace, and they don't
require any permissions to use.

### Identifying split views

Every `Tab` object contains a
[`splitViewId` property](https://developer.chrome.com/docs/extensions/reference/api/tabs#:%7E:text=the%20sessions%20API.-,splitViewId,-number%C2%A0optional).
If the tab is part of a split view, it shares a unique identifier with its
paired tab; otherwise, the `splitViewId` defaults to -1.

``` js
// Querying all split views in the current windows
const tabs = await browser.tabs.query({ currentWindow: true });
const splitViews = tabs.map(tab => tab.splitViewId).filter(splitViewId => splitViewId !== -1);
```

### General constraints

In order for two tabs to be able to join a split view, they must meet the following requirements:

1. Tabs must be (or created) adjacent to each other.
2. Tabs must not be already in a split view.
3. Tabs must have the same `pinned` ,`windowId` , and`groupId` state.

Conversely, when two tabs are unsplit, they will retain the same `pinned`,
`windowId`, `groupId` states along with the relative positioning to each
other.

### Creating split views

There are two methods by which an extension can create a new split view:

1. Create a new tab that will split with an existing tab using the new
`splitWithTabId` parameter in`browser.tabs.create` .
2. Pair two existing tabs with the new `browser.tabs.createSplit` method.

#### Examples

You can create a new tab using `splitWithTabId` to split with an existing tab.

```
await browser.tabs.create({splitWithTabId: existingTab.id});
```

By default, the new tab will be created to the *right* of the existing tab.

To create a new tab to the *left* of the existing tab, set the index as that
tab's index:

```
  await browser.tabs.create({splitWithTabId: existingTab.id, index: existingTab.index});
```

You can also create a new split view by pairing two existing tabs.

```
  await browser.tabs.createSplit([existingTab1.id, existingTab2.id]);
```

### Unsplitting split views

To separate a split view into two independent tabs, an extension can use the
new `browser.tabs.unsplit` method.

``` js
const splitViewId = browser.tabs.createSplit([tab1.id, tab2.id]);
// Unsplitting the split view into two independent tabs
await browser.tabs.unsplit(splitViewId);
```

## Learn more

We hope this new capability will supercharge more productive workflows for your
extensions. To start building extensions with split view capabilities, check out
the [Tabs API](https://developer.chrome.com/docs/extensions/reference/api/tabs)
documentation. If you have any questions or need help with the Split View API,
visit the
[Chromium extensions](https://groups.google.com/a/chromium.org/g/chromium-extensions?e=48417069)
Google Group.

Happy splitting!