Injects CSS into a page.
To use this API you must have the permission for the page's URL, either explicitly as a host permission, or using the activeTab permission.
You can only inject CSS into pages whose URL can be expressed using a match pattern: meaning, its scheme must be one of "http", "https", "file", "ftp". This means that you can't inject CSS into any of the browser's built-in pages, such as about:debugging, about:addons, or the page that opens when you open a new empty tab.
The inserted CSS may be removed again by calling tabs.removeCSS()
.
This is an asynchronous function that returns a Promise
.
Syntax
var inserting = browser.tabs.insertCSS( tabId, // optional integer details // object )
Parameters
tabId
Optionalinteger
. The ID of the tab in which to insert the CSS. Defaults to the active tab of the current window.details
- An object describing the CSS to insert. It contains the following properties:
-
allFrames
Optionalboolean
. Iftrue
, the CSS will be injected into all frames of the current page. If it isfalse
, CSS is only injected into the top frame. Defaults tofalse
.code
Optionalstring
. Code to inject, as a text string.cssOrigin
Optionalstring
. This can take one of two values: "user", to add the CSS as a user stylesheet, or "author" to add it as an author stylesheet. Specifying "user" enables you to prevent websites from overriding the CSS you insert: see Cascading order. If this option is omitted, the CSS is added as an author stylesheet.file
Optionalstring
. Path to a file containing the code to inject. In Firefox, relative URLs are resolved relative to the current page URL. In Chrome, these URLs are resolved relative to the extension's base URL. To work cross-browser, you can specify the path as an absolute URL, starting at the extension's root, like this:"/path/to/stylesheet.css"
.frameId
Optionalinteger
. The frame where the CSS should be injected. Defaults to0
(the top-level frame).matchAboutBlank
Optionalboolean
. Iftrue
, the code will be injected into embedded "about:blank" and "about:srcdoc" frames if your extension has access to their parent document. The code cannot be inserted in top-level about: frames. Defaults tofalse
.runAt
OptionalextensionTypes.RunAt
. The soonest that the code will be injected into the tab. Defaults to "document_idle".
Return value
A Promise
that will be fulfilled with no arguments when all the CSS has been inserted. If any error occurs, the promise will be rejected with an error message.
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Chrome | Edge | Firefox | Firefox for Android | Opera | |
---|---|---|---|---|---|
Basic support | Yes | Yes | 47 | 54 | Yes |
runAt | 20 | No | 47 | 54 | 15 |
frameId | 39 | Yes | 47 | 54 | 26 |
matchAboutBlank | 39 | Yes | No | No | 26 |
cssOrigin | No | No | 53 | 54 | No |
Examples
This example inserts into the currently active tab CSS which is taken from a string.
var css = "body { border: 20px dotted pink; }"; browser.browserAction.onClicked.addListener(() => { function onError(error) { console.log(`Error: ${error}`); } var insertingCSS = browser.tabs.insertCSS({code: css}); insertingCSS.then(null, onError); });
This example inserts CSS which is loaded from a file packaged with the extension. The CSS is inserted into the tab whose ID is 2:
browser.browserAction.onClicked.addListener(() => { function onError(error) { console.log(`Error: ${error}`); } var insertingCSS = browser.tabs.insertCSS(2, {file: "content-style.css"}); insertingCSS.then(null, onError); });
Example extensions
This API is based on Chromium's chrome.tabs
API. This documentation is derived from tabs.json
in the Chromium code.
Microsoft Edge compatibility data is supplied by Microsoft Corporation and is included here under the Creative Commons Attribution 3.0 United States License.
// Copyright 2015 The Chromium Authors. All rights reserved. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following disclaimer // in the documentation and/or other materials provided with the // distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived from // this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.