CKEditor (formerly known as FCKeditor) is a

WYSIWYG In computing, WYSIWYG ( ), an acronym for What You See Is What You Get, is a system in which editing software allows content to be edited in a form that resembles its appearance when printed or displayed as a finished product, such as a printed d ...

rich text editor which enables writing content directly inside of web pages or online applications. Its core code is written in

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of websites use JavaScript on the client side for webpage behavior, of ...

and it is developed by CKSource. CKEditor is available under open source and commercial licenses.

History

FCKeditor and CKEditor 3

The first version of CKEditor, under the name FCKeditor, was released in March 2003 by Frederico Caldeira Knabben, the creator of the editor and the project's Benevolent Dictator for Life. After reaching more than 3 million downloads, FCKeditor was completely reviewed and redesigned into CKEditor 3, with special attention given to performance, accessibility and a new UI.

CKEditor 4

In December 2012, CKEditor 4 was released with an Inline Editing solution, reformatted source code, enhanced DOM and CSS performance. The server-side implementations were removed.

CKEditor 5

After five years, in 2018, CKEditor 5 first stable version was introduced. With its code rewritten from scratch, CKEditor 5 has a custom data model and architecture. The editor implements

Operational Transformation Operational transformation (OT) is a technology for supporting a range of collaboration functionalities in advanced collaborative software systems. OT was originally invented for consistency maintenance and concurrency control in collaborative edit ...

for the tree-structured model as well as many other mechanisms which were required to create a real-time collaborative UX. CKEditor 5 is a JavaScript framework offering a rich API to develop any editing solution. CKEditor 5 also offers builds, which are ready-to-use editors; there are currently 5 builds available to download: Classic, Inline, Balloon, Balloon block and Document.

CKEditor Ecosystem

In October 2017, CKSource launched the CKEditor Ecosystem. As of 2022 it consists of the following products: * CKEditor 4. * CKEditor 5 Builds and CKEditor 5 Framework. * CKBox, a standalone and integrated image upload and management service. * CKEditor Cloud Services, a cloud platform with editing features and real-time collaboration services.

Features

CKEditor 4 has features found in

desktop A desktop traditionally refers to: * The surface of a desk (often to distinguish office appliances that fit on a desk, such as photocopiers and printers, from larger equipment covering its own area on the floor) Desktop may refer to various compu ...

word processors such as styles formatting (bold, italic, underline, bulleted and numbered lists), tables, block quoting, web resource linking, safe undo function, image inserting, paste from

Word A word is a basic element of language that carries an objective or practical meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no conse ...

and other common HTML formatting tools. Also CKEditor 4 has built-in spell checker functionality provided as plug-ins b
WebSpellChecker
LLC. By default, it is available for free with a banner ad. It checks the spelling of the text and marks all errors with a red wavy line and allows the user to choose one of the correct suggestions. There are currently many plugins available with CKEditor 4 to serve different needs, e.g. CKFinder and Accessibility Checker (the CKSource's plugins). CKFinder is a file manager for including files and images within content created with the editors. It is compatible with both CKEditor 4 and 5 and is available under commercial license. Accessibility Checker is available under both Open Source and commercial licenses.

Real-time collaborative editing

CKEditor 5's architecture and custom data model makes it possible to enable

real-time collaborative editing A collaborative real-time editor is a type of collaborative software or web application which enables real-time collaborative editing, simultaneous editing, or live editing of the same digital document, computer file or cloud-stored data – s ...

. A custom collaborative solution can be built by using the CKEditor 5 Framework components and real-time collaborative editing can be enabled by connecting to the CKEditor Cloud Services. A ready to use, drop-in component based on CKEditor 5 (Letters) offers a complete solution for real-time collaborative writing.

Browser compatibility

CKEditor 4 is fully compatible with most internet browsers, including latest stable releases from Google Chrome,

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current ...

, Safari,

Microsoft Edge Microsoft Edge is a proprietary, cross-platform web browser created by Microsoft. It was first released in 2015 as part of Windows 10 and Xbox One and later ported to other platforms as a fork of Google's Chromium open-source project: Android ...

Opera Opera is a form of theatre in which music is a fundamental component and dramatic roles are taken by singers. Such a "work" (the literal translation of the Italian word "opera") is typically a collaboration between a composer and a libr ...

and

Internet Explorer Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft which was used in the Windows line of operating systems ( ...

10 and 11. In mobile environments, it has close to full support in Safari (iOS6 +) and Chrome (Android). CKEditor 5 is also compatible with Google Chrome, Firefox, Safari, Opera and Microsoft Edge. However, it does not support Internet Explorer 11 yet.

References

External links

CKSource Official Website

CKEditor 4 GitHub repository

CKEditor 5 GitHub repository
{{HTML editors Free text editors Free HTML editors JavaScript-based HTML editors Joomla extensions Drupal