tabs.toggleReaderMode()

Toggles Reader Mode for the given tab.

This function toggles Reader Mode for the given tab. It takes a tab ID as a parameter: if this is omitted, the currently active tab is toggled.

This is an asynchronous function that returns a Promise.

Reader Mode, also known as Reader View, is a browser feature that makes it easier for the user to focus on an article by:

  • hiding non-essential page elements like sidebars, footers, and ads
  • changing the page's text size, contrast and layout for better readability.

Reader Mode is useful specifically for articles: meaning, pages that have a body of text content as their main feature. Pages that don't have an identifiable article are not eligible for display in Reader Mode. To find out whether a page is an article, check the isArticle property of tabs.Tab.

To find out whether a tab is already in Reader Mode, check the isInReaderMode property of tabs.Tab. To track tabs changing into or out of Reader Mode, you'll need to keep track of the current state of all tabs, and check when isInReaderMode changes:

function handleUpdated(tabId, changeInfo, tabInfo) {
  if (changeInfo.status === "complete") {
    console.log(`Tab ${tabId} reader mode: ${tabInfo.isInReaderMode}`);
  }
}

browser.tabs.onUpdated.addListener(handleUpdated);

Syntax

var toggling = browser.tabs.toggleReaderMode(
  tabId            // optional integer
)

Parameters

tabIdOptional
integer. The ID of the tab to display in Reader Mode. Defaults to the selected tab of the current window.

Return value

A Promise that will be fulfilled with no arguments when the tab has been updated. If any error occurs (for example, because the page was not an article), the promise will be rejected with an error message.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxOperaFirefox for Android
Basic supportChrome No support NoEdge No support NoFirefox Full support 58Opera No support NoFirefox Android No support No

Legend

Full support  
Full support
No support  
No support

Examples

This code switches every new page into Reader Mode, if that page is eligible for it:

function switchToReaderMode(tabId, changeInfo, tabInfo) {
  if (changeInfo.isArticle) {
    browser.tabs.toggleReaderMode(tabId);
  }
}

browser.tabs.onUpdated.addListener(switchToReaderMode);

Document Tags and Contributors

Contributors to this page: wbamberg
Last updated by: wbamberg,