Equation Editor

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Videos featuring the Editor *

CK Editor v4.x (plugin v2.2)

A CK Editor plugin that allows equations to be created in HTML.



  • To create a new equation, first click within the text area where you need to add the equation.
  • Click the fx button on the CK Editor toolbar. This launches the Equation Editor.
  • Create your equation.
  • Select Copy to document to insert the equation into your document at the cursor position.
  • Double-click existing equations to edit them in the Equation Editor.

CK Editor
Example toolbar: CodeCogs Equation Editor button highlighted in a red circle.

Quick Installation

  1. Install the CK Editor.
  2. Download and uncompress it to your desktop or server.
  3. Find the folder where you installed CK Editor. For our purposes we will assume this is ~/ckeditor.
  4. Open the CK Editor plugins folder, ~/ckeditor/plugins and copy in the directory equation from the uncompressed folder.
  5. Modify the config.js to load the plugin by adding config.extraPlugins = 'equation'; as follows:
    CKEDITOR.editorConfig = function( config )
    config.extraPlugins = 'eqneditor';

    config.toolbarGroups = [
    { name: 'clipboard', groups: [ 'clipboard', 'undo' ] },
    { name: 'links' },
    { name: 'insert' },
    { name: 'forms' },
    { name: 'tools' },
    { name: 'others' },
    { name: 'basicstyles', groups: [ 'basicstyles', 'cleanup' ] },
    { name: 'styles' },
    { name: 'colors' },
    { name: 'about' }

  6. Integrate the CK Editor into your HTML page and load in the normal way. The CodeCogs Equation Editor will appear within the insert toolbar Group.
  7. If you do make your own custom toolbar, make sure to include Equation in the list of buttons, e.g:
    <textarea id="editor1" name="editor1"></textarea>
    <script type="text/javascript">
    CKEDITOR.replace( 'editor1', { toolbar : [ [ 'EqnEditor', 'Bold', 'Italic' ] ] });

Change History

  • v1.2 - Our first version for CKEditor v4, which builds on our earlier version for CKEditor v3
  • v1.3 - Improvement support for secure websites. Fixed bug that prevented equations being edited.
  • v2 - Improved integration with the CKEditor, using CKEditor dialogs that appear on page.
  • v2.1 - Bug fix that allows more Eqn plugings to work with multiple edit areas on a single page.
  • v2.2 - General update in line with the movement of CodeCogs to new servers. (Recommended upgrade).