tabs.removeCSS()

{{AddonSidebar}} 

Removes from a page CSS which was previously injected by a call to {{WebExtAPIRef("tabs.insertCSS()")}} .

[!NOTE] When using Manifest V3 or higher, use {{WebExtAPIRef("scripting.insertCSS()")}}  and {{WebExtAPIRef("scripting.removeCSS()")}}  to insert and remove CSS.

This is an asynchronous function that returns a Promise.

Syntax

let removing = browser.tabs.removeCSS(
  tabId,           // optional integer
  details          // object
)

Parameters

• tabId {{optional_inline}} 

  • : integer. The ID of the tab from which to remove the CSS. Defaults to the active tab of the current window.

• details

  • : An object describing the CSS to remove from the page. It contains the following properties:

    • allFrames {{optional_inline}} 
      • : boolean. If true, the code will be removed from all frames of the current page. If it is false, code is only removed from the top frame. Defaults to false.
    • code {{optional_inline}} 
      • : string. CSS to remove, as a text string. This must exactly match a CSS string previously inserted into the page using {{WebExtAPIRef("tabs.insertCSS()")}} .
    • cssOrigin {{optional_inline}} 
      • : string. This can take one of two values: “user”, for CSS added as a user stylesheet, or “author” for CSS added as an author stylesheet. If this option was set previously by {{WebExtAPIRef("tabs.insertCSS()")}} , then it must exactly match.
    • file {{optional_inline}} 
      • : string. Path to a file containing the CSS to remove. This must exactly match a CSS file previously inserted into the page using {{WebExtAPIRef("tabs.insertCSS()")}} .
    • frameId {{optional_inline}} 
      • : integer. The frame from which to remove the CSS. Defaults to 0 (the top-level frame).
    • matchAboutBlank {{optional_inline}} 
      • : boolean. If true, the CSS will be removed from embedded “about:blank” and “about:srcdoc” frames if your extension has access to their parent document. Defaults to false.

Return value

A Promise that will be fulfilled with no arguments when all the CSS has been removed. If any error occurs, the promise will be rejected with an error message.

Examples

This example adds some CSS using {{WebExtAPIRef("tabs.insertCSS")}} , then removes it again when the user clicks a browser action:

let css = "body { border: 20px dotted pink; }";

function onError(error) {
  console.log(`Error: ${error}`);
}

let insertingCSS = browser.tabs.insertCSS(2, { code: css });
insertingCSS.then(null, onError);

browser.browserAction.onClicked.addListener(() => {
  let removing = browser.tabs.removeCSS(2, { code: css });
  removing.then(null, onError);
});

{{WebExtExamples}} 

Browser compatibility

{{Compat}} 

[!NOTE] This API is based on Chromium’s chrome.tabs API. This documentation is derived from tabs.json in the Chromium code.