ryrodriguez25 · pull · Apr 2, 2026 · Apr 2, 2026 · Apr 2, 2026 · Apr 2, 2026
diff --git a/files/en-us/mozilla/add-ons/webextensions/api/browseraction/isenabled/index.md b/files/en-us/mozilla/add-ons/webextensions/api/browseraction/isenabled/index.md
@@ -19,7 +19,7 @@ let gettingIsEnabled = browser.browserAction.isEnabled(
 ### Parameters
 
 - `details` {{optional_inline}}
-  - : `integer` or `object`. An an `integer` it defines the ID of a tab to check. As an `object` it contains:
+  - : `integer` or `object`. As an `integer` it defines the ID of a tab to check. As an `object` it contains:
     - `tabId` {{optional_inline}}
       - : `integer`. ID of a tab to check.
     - `windowId` {{optional_inline}}

diff --git a/files/en-us/mozilla/firefox/releases/149/index.md b/files/en-us/mozilla/firefox/releases/149/index.md
@@ -47,7 +47,7 @@ Firefox 149 was released on [March 24, 2026](https://whattrainisitnow.com/releas
   A serialized version of the report objects can also be sent to a reporting server specified in the corresponding HTTP header — endpoint names and corresponding URLs must first be defined in the {{httpheader('Reporting-Endpoints')}} or {{httpheader('Report-To')}} HTTP response headers.
   ([Firefox bug 1976074](https://bugzil.la/1976074), [Firefox bug 2008916](https://bugzil.la/2008916)).
 
-- Up to Firefox 148, `structuredClone.call(iframe.contentWindow)` incorrectly created objects in the caller's [realm](/en-US/docs/Web/JavaScript/Reference/Execution_model#realms) instead of the iframe's realm. The implementation now instantiates objects in the `this` realm, so the method's behavior more closely matched the specification.
+- Up to Firefox 148, `structuredClone.call(iframe.contentWindow)` incorrectly created objects in the caller's [realm](/en-US/docs/Web/JavaScript/Reference/Execution_model#realms) instead of the iframe's realm. The implementation now instantiates objects in the `this` realm, so the method's behavior more closely matched the specification ([Firefox bug 2017797](https://bugzil.la/2017797)).
 
 #### DOM
 
@@ -108,8 +108,7 @@ Firefox 149 was released on [March 24, 2026](https://whattrainisitnow.com/releas
 - Adds support for `tabId` as a top-level parameter in {{WebExtAPIRef("action.isEnabled")}} and {{WebExtAPIRef("browserAction.isEnabled")}}. This change provides for compatibility with the Chrome implementation of `action.isEnabled`. ([Firefox bug 2013477](https://bugzil.la/2013477))
 - A user gesture is no longer required for {{WebExtAPIRef("action.openPopup")}} and {{WebExtAPIRef("browserAction.openPopup")}} to open a popup. This feature was available behind the `extensions.openPopupWithoutUserGesture.enabled` preference from Firefox 108. This change aligns Firefox's behavior with Chrome and Safari. ([Firefox bug 1799344](https://bugzil.la/1799344))
 - If `windowId` is passed in {{WebExtAPIRef("action.openPopup")}} or {{WebExtAPIRef("browserAction.openPopup")}}, the window must be focused (active) for the popup to open. To open a popup in an unfocused window {{WebExtAPIRef("windows.update","windows.update(windowId, { focused: true })")}} must be called first. This change aligns Firefox behavior with Chrome. ([Firefox bug 2011516](https://bugzil.la/2011516))
-- The implementation of {{domxref("structuredClone")}} has changed to instantiate objects in the `this` realm instead of the caller's realm. For backwards compatibility, the global scope of content scripts now includes its own `structuredClone` method that shadows the `window.structuredClone` method. For more information, see [`structuredClone` in Sharing objects with page scripts](/en-US/docs/Mozilla/Add-ons/WebExtensions/Sharing_objects_with_page_scripts#structuredclone).
-
+- The implementation of {{domxref("structuredClone")}} has changed to instantiate objects in the `this` realm instead of the caller's realm. For backwards compatibility, the global scope of content scripts now includes its own `structuredClone` method that shadows the `window.structuredClone` method. For more information, see [`structuredClone` in Sharing objects with page scripts](/en-US/docs/Mozilla/Add-ons/WebExtensions/Sharing_objects_with_page_scripts#structuredclone) ([Firefox bug 2017797](https://bugzil.la/2017797)).
 - The ability of extensions to dynamically execute code in their `moz-extension:` documents with {{WebExtAPIRef("tabs.executeScript")}}, {{WebExtAPIRef("tabs.insertCSS")}}, {{WebExtAPIRef("tabs.removeCSS")}}, {{WebExtAPIRef("scripting.executeScript")}}, {{WebExtAPIRef("scripting.insertCSS")}}, and {{WebExtAPIRef("scripting.removeCSS")}} is deprecated. ([Firefox bug 2011234](https://bugzil.la/2011234)) The feature is no longer available in Firefox Nightly, and the beta and release versions of Firefox provide a warning in the tab's console. This restriction will apply to all versions of Firefox 152 and later. ([Firefox bug 2015559](https://bugzil.la/2015559)) As an alternative, an extension can run code in its documents dynamically by registering a {{WebExtAPIRef("runtime.onMessage")}} listener in the document's script, then sending a message to trigger execution of the required code.
 - The implicit CSS filter applied to [page action](/en-US/docs/Mozilla/Add-ons/WebExtensions/user_interface/Page_actions) SVG icons on dark themes is deactivated in Nightly builds ([Firefox bug 2001318](https://bugzil.la/2001318)) and will be deactivated in other Firefox editions from version 152 ([Firefox bug 2016509](https://bugzil.la/2016509)). You can test page action SVG icons with the CSS filter disabled in other Firefox editions by creating a boolean `about:config` preference called `extensions.webextensions.pageActionIconDarkModeFilter.enabled` and setting it to `false`.
 

diff --git a/files/en-us/web/api/cookiestore/index.md b/files/en-us/web/api/cookiestore/index.md
@@ -116,7 +116,7 @@ async function cookieTest() {
   }
 
   // Set cookie using document.cookie
-  // (to demonstrate these are are fetched too)
+  // (to demonstrate these are fetched too)
   document.cookie = "favorite_food=tripe; SameSite=None; Secure";
 
   // Get named cookie and log properties

diff --git a/files/en-us/web/api/cspviolationreport/columnnumber/index.md b/files/en-us/web/api/cspviolationreport/columnnumber/index.md
@@ -10,7 +10,7 @@ browser-compat: api.ReportingObserver.ReportingObserver.options_parameter.types_
 
 The **`columnNumber`** property of the {{domxref("CSPViolationReport")}} dictionary indicates the character position in the source file line that triggered the [Content Security Policy (CSP)](/en-US/docs/Web/HTTP/Guides/CSP) violation.
 
-This property is used with the {{domxref("CSPViolationReport.sourceFile")}} and {{domxref("CSPViolationReport.lineNumber")}} properties, which together provide the the exact location in the source that caused the violation.
+This property is used with the {{domxref("CSPViolationReport.sourceFile")}} and {{domxref("CSPViolationReport.lineNumber")}} properties, which together provide the exact location in the source that caused the violation.
 
 Note that the browser extracts the value from _the global object_ of the file that triggered the violation.
 If the resource that triggers the CSP violation is not loaded, the value will be `null`.

diff --git a/files/en-us/web/api/document/execcommand/index.md b/files/en-us/web/api/document/execcommand/index.md
@@ -68,7 +68,7 @@ execCommand(commandName, showDefaultUI, valueArgument)
       - : Deletes the character ahead of the [cursor](https://en.wikipedia.org/wiki/Cursor_%28computers%29)'s position, identical to hitting the Delete key on a Windows keyboard.
     - `heading`
       - : Adds a heading element around a selection or insertion point line. Requires the tag-name string as a value argument (i.e., `"H1"`, `"H6"`). (Not supported by Safari.)
-    - `highlightColor`
+    - `hiliteColor`
       - : Changes the background color for the selection or at the insertion point. Requires a color value string as a value argument. `useCSS` must be `true` for this to function.
     - `increaseFontSize`
       - : Adds a {{HTMLElement("big")}} tag around the selection or at the insertion point.
@@ -91,6 +91,8 @@ execCommand(commandName, showDefaultUI, valueArgument)
 
     - `insertImage`
       - : Inserts an image at the insertion point (deletes selection). Requires a URL string for the image's `src` as a value argument. The requirements for this string are the same as `createLink`.
+    - `insertLineBreak`
+      - : Deletes the selection, and replaces it with a [line break element](/en-US/docs/Web/HTML/Reference/Elements/br).
     - `insertOrderedList`
       - : Creates a [numbered ordered list](/en-US/docs/Web/HTML/Reference/Elements/ol) for the selection or at the insertion point.
     - `insertUnorderedList`

diff --git a/files/en-us/web/api/htmlgeolocationelement/initialpermissionstatus/index.md b/files/en-us/web/api/htmlgeolocationelement/initialpermissionstatus/index.md
@@ -83,7 +83,7 @@ if (geo.initialPermissionStatus === "prompt") {
 }
 ```
 
-Finally, we we add a {{domxref("HTMLGeolocationElement.location_event", "location")}} event listener to the `HTMLGeolocationElement` object, to detect when the location data request is returned. If the data is returned successfully, we access it via the {{domxref("HTMLGeolocationElement.position")}} property, and print the latitude and longitude values to the output paragraph. If the data request fails, we access the error via the {{domxref("HTMLGeolocationElement.error")}} property and print it to the output paragraph.
+Finally, we add a {{domxref("HTMLGeolocationElement.location_event", "location")}} event listener to the `HTMLGeolocationElement` object, to detect when the location data request is returned. If the data is returned successfully, we access it via the {{domxref("HTMLGeolocationElement.position")}} property, and print the latitude and longitude values to the output paragraph. If the data request fails, we access the error via the {{domxref("HTMLGeolocationElement.error")}} property and print it to the output paragraph.
 
 ```js
 geo.addEventListener("location", () => {

diff --git a/files/en-us/web/api/navigateevent/intercept/index.md b/files/en-us/web/api/navigateevent/intercept/index.md
@@ -119,7 +119,7 @@ The `precommitHandler()` callback takes a {{domxref("NavigationPrecommitControll
 
 ### Scheduling post-commit actions in `precommitHandler()`
 
-As we saw above, you can specify a `handler()` callback in the object passed to the `intercept()` method in order to preform actions after a navigation is is committed.
+As we saw above, you can specify a `handler()` callback in the object passed to the `intercept()` method in order to preform actions after a navigation is committed.
 This approach works well if the actions required after commit do not depend on any actions run in the pre-commit phase.
 If they do, then you can use {{domxref("NavigationPrecommitController.addHandler()")}} in `precommitHandler()` to dynamically add a handler that will run after the navigation commits.
 

diff --git a/files/en-us/web/api/worker/worker/index.md b/files/en-us/web/api/worker/worker/index.md
@@ -70,7 +70,7 @@ If a cross-origin worker is required, users must load it from an intermediate sa
 
 ### Module and classic workers
 
-A classic worker is one that that is constructed from a classic script, while a module worker is constructed from an [ECMASCript module](/en-US/docs/Web/JavaScript/Guide/Modules).
+A classic worker is one that is constructed from a classic script, while a module worker is constructed from an [ECMASCript module](/en-US/docs/Web/JavaScript/Guide/Modules).
 The type of worker affects the worker constructor options, how the worker script is fetched, and how it is executed.
 
 The code below shows two ways you can construct a classic worker, and also how you specify the `type` of `"module"` to create a module worker.

diff --git a/files/en-us/web/css/guides/scroll-driven_animations/timeline_range_names/index.md b/files/en-us/web/css/guides/scroll-driven_animations/timeline_range_names/index.md
@@ -505,7 +505,7 @@ body::before {
 }
 ```
 
-Select the the different height values, then scroll to compare `entry` with `entry-crossing` for each size.
+Select the different height values, then scroll to compare `entry` with `entry-crossing` for each size.
 
 {{EmbedLiveSample("entry_crossing", "100%", "400")}}
 

diff --git a/files/en-us/web/css/reference/properties/background-attachment/index.md b/files/en-us/web/css/reference/properties/background-attachment/index.md
@@ -222,7 +222,7 @@ ul {
 
 {{EmbedLiveSample("Multiple_background_images")}}
 
-Note how the first background image is fixed to the viewport while the the second background image is fixed relative to the list.
+Note how the first background image is fixed to the viewport while the second background image is fixed relative to the list.
 
 ## Specifications
 

diff --git a/files/en-us/web/security/authentication/passkeys/index.md b/files/en-us/web/security/authentication/passkeys/index.md
@@ -60,7 +60,7 @@ The RP's front-end code sends this to the server, which:
 
 - Verifies the attestation, if attestation is taking place
 - Verifies that the challenge is the expected value
-- Creates a new user account and stores the public key in it along with with the user's account information.
+- Creates a new user account and stores the public key in it along with the user's account information.
 
 ## Sign in
 

diff --git a/files/en-us/webassembly/reference/memory/grow/index.md b/files/en-us/webassembly/reference/memory/grow/index.md
@@ -25,7 +25,7 @@ Currently each page is 64KiB.
 
     ;; grow memory by 1 page
     ;; grow returns in 1 for success and -1 for failure
-    ;; will fail if you change to more more than 1 page
+    ;; will fail if you change to more than 1 page
     (memory.grow (i32.const 1))
     call $log ;; log the result
-Original file line number
+Diff line change
@@ Expand Up / @@ -83,7 +83,7 @@ if (geo.initialPermissionStatus === "prompt") { @@
     }
     ```
-    Finally, we we add a {{domxref("HTMLGeolocationElement.location_event", "location")}} event listener to the `HTMLGeolocationElement` object, to detect when the location data request is returned. If the data is returned successfully, we access it via the {{domxref("HTMLGeolocationElement.position")}} property, and print the latitude and longitude values to the output paragraph. If the data request fails, we access the error via the {{domxref("HTMLGeolocationElement.error")}} property and print it to the output paragraph.
+    Finally, we add a {{domxref("HTMLGeolocationElement.location_event", "location")}} event listener to the `HTMLGeolocationElement` object, to detect when the location data request is returned. If the data is returned successfully, we access it via the {{domxref("HTMLGeolocationElement.position")}} property, and print the latitude and longitude values to the output paragraph. If the data request fails, we access the error via the {{domxref("HTMLGeolocationElement.error")}} property and print it to the output paragraph.
     ```js
     geo.addEventListener("location", () => {
@@ Expand Down @@