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When an HTML document has been switched to designMode, the document object exposes the execCommand method which allows one to run commands to manipulate the contents of the editable region. Most commands affect the document's selection (bold, italics, etc.), while others insert new elements (adding a link) or affect an entire line (indenting). When using contentEditable, calling execCommand will affect the currently active editable element.

Syntax

execCommand(aCommandName, aShowDefaultUI, aValueArgument)

Parameters

aCommandName
A DOMString representing the name of the command
aShowDefaultUI
A Boolean indicating whether the default user interface should be shown. This is not implemented in Mozilla.

aValueArgument

A DOMString representing some commands (such as insertimage) require an extra value argument (the image's url). Pass an argument of null if no argument is needed.

Commands

backColor
Changes the document background color. In styleWithCss mode, it affects the background color of the containing block instead. This requires a color value string to be passed in as a value argument. (Internet Explorer uses this to set text background color.)
bold
Toggles bold on/off for the selection or at the insertion point. (Internet Explorer uses the STRONG tag instead of B.)
contentReadOnly
Makes the content document either read-only or editable. This requires a boolean true/false to be passed in as a value argument. (Not supported by Internet Explorer.)
copy
Copies the current selection to the clipboard. Conditions of having this behavior enabled varies from one browser to another, and have evolved over time. Check the compatibility table for knowing if you can use it in your case.
createLink
Creates an anchor link from the selection, only if there is a selection. This requires the HREF URI string to be passed in as a value argument. The URI must contain at least a single character, which may be a white space. (Internet Explorer will create a link with a null URI value.)
cut
Cuts the current selection and copies it to the clipboard. Conditions of having this behavior enabled varies from one browser to another, and have evolved over time. Check the compatibility table for knowing if you can use it in your case.
decreaseFontSize
Adds a <small> tag around the selection or at the insertion point. (Not supported by Internet Explorer.)
delete
Deletes the current selection.
enableInlineTableEditing
Enables or disables the table row and column insertion and deletion controls. (Not supported by Internet Explorer.)
enableObjectResizing
Enables or disables the resize handles on images and other resizable objects. (Not supported by Internet Explorer.)
fontName
Changes the font name for the selection or at the insertion point. This requires a font name string ("Arial" for example) to be passed in as a value argument.
fontSize
Changes the font size for the selection or at the insertion point. This requires an HTML font size (1-7) to be passed in as a value argument.
foreColor
Changes a font color for the selection or at the insertion point. This requires a color value string to be passed in as a value argument.
formatBlock
Adds an HTML block-style tag around the line containing the current selection, replacing the block element containing the line if one exists (in Firefox, BLOCKQUOTE is the exception - it will wrap any containing block element). Requires a tag-name string to be passed in as a value argument. Virtually all block style tags can be used (eg. "H1", "P", "DL", "BLOCKQUOTE"). (Internet Explorer supports only heading tags H1 - H6, ADDRESS, and PRE, which must also include the tag delimiters < >, such as "<H1>".)
forwardDelete
Deletes the character ahead of the cursor's position.  It is the same as hitting the delete key.
heading
Adds a heading tag around a selection or insertion point line. Requires the tag-name string to be passed in as a value argument (i.e. "H1", "H6"). (Not supported by Internet Explorer and Safari.)
hiliteColor
Changes the background color for the selection or at the insertion point. Requires a color value string to be passed in as a value argument. UseCSS must be turned on for this to function. (Not supported by Internet Explorer.)
increaseFontSize
Adds a BIG tag around the selection or at the insertion point. (Not supported by Internet Explorer.)
indent
Indents the line containing the selection or insertion point. In Firefox, if the selection spans multiple lines at different levels of indentation, only the least indented lines in the selection will be indented.
insertBrOnReturn
Controls whether the Enter key inserts a br tag or splits the current block element into two. (Not supported by Internet Explorer.)
insertHorizontalRule
Inserts a horizontal rule at the insertion point (deletes selection).
insertHTML
Inserts an HTML string at the insertion point (deletes selection). Requires a valid HTML string to be passed in as a value argument. (Not supported by Internet Explorer.)
insertImage
Inserts an image at the insertion point (deletes selection). Requires the image SRC URI string to be passed in as a value argument. The URI must contain at least a single character, which may be a white space. (Internet Explorer will create a link with a null URI value.)
insertOrderedList
Creates a numbered ordered list for the selection or at the insertion point.
insertUnorderedList
Creates a bulleted unordered list for the selection or at the insertion point.
insertParagraph
Inserts a paragraph around the selection or the current line. (Internet Explorer inserts a paragraph at the insertion point and deletes the selection.)
insertText
Inserts the given plain text at the insertion point (deletes selection).
italic
Toggles italics on/off for the selection or at the insertion point. (Internet Explorer uses the EM tag instead of I.)
justifyCenter
Centers the selection or insertion point.
justifyFull
Justifies the selection or insertion point.
justifyLeft
Justifies the selection or insertion point to the left.
justifyRight
Right-justifies the selection or the insertion point.
outdent
Outdents the line containing the selection or insertion point.
paste
Pastes the clipboard contents at the insertion point (replaces current selection). Clipboard capability must be enabled in the user.js preference file. See [1].
redo
Redoes the previous undo command.
removeFormat
Removes all formatting from the current selection.
selectAll
Selects all of the content of the editable region.
strikeThrough
Toggles strikethrough on/off for the selection or at the insertion point.
subscript
Toggles subscript on/off for the selection or at the insertion point.
superscript
Toggles superscript on/off for the selection or at the insertion point.
underline
Toggles underline on/off for the selection or at the insertion point.
undo
Undoes the last executed command.
unlink
Removes the anchor tag from a selected anchor link.
useCSS
Toggles the use of HTML tags or CSS for the generated markup. Requires a boolean true/false as a value argument. NOTE: This argument is logically backwards (i.e. use false to use CSS, true to use HTML). (Not supported by Internet Explorer.) This has been deprecated; use the styleWithCSS command instead.
styleWithCSS
Replaces the useCSS command; argument works as expected, i.e. true modifies/generates style attributes in markup, false generates formatting elements.

Example

An example of how to use it on CodePen.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) ? ? (Yes)
insertBrOnReturn Not supported (Yes) Not supported Not supported Not supported
copy/cut 42 41 (41) 9.0 29.0 Not supported
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? (Yes) (Yes) ? ? ?
insertBrOnReturn Not supported Not supported (Yes) Not supported Not supported Not supported
copy/cut Not supported (42) 41.0 (41) ? ? Not supported

See Scribe's "Browser Inconsistencies" documentation for a list of many browser bugs related to document.execCommand.?

[1] Before Firefox 41, clipboard capability needed to be enabled in the user.js preference file. See A brief guide to Mozilla preferences for more information. In Firefox 41 and later, clipboard capability are enabled by default in any event handler that is able to pop-up a window (semi-trusted scripts).

Specification

Specification Status Comment
HTML Editing APIs
The definition of 'execCommand' in that specification.
Editor's Draft  

See also

Document Tags and Contributors

Last updated by: Sheppy,
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