CKEditor 5 changelog

This is the CKEditor 5 changelog guide. Here you will find information about the most important changes introduced in the release, new features, and bug fixes.

Information about both major and minor breaking changes is available, too, if the release introduces them. You can read more about breaking changes in CKEditor 5 in the Versioning policy guide.

You can find more information about each release in the blog posts linked at the start of each entry.

This guide provides the changelog information for the 3 latest releases of CKEditor 5. For older releases, refer to the release notes on GitHub.

# CKEditor 5 44.3.0 release

We are happy to announce the release of CKEditor 5 v44.3.0.

# Release Highlights

This release brings a couple of minor improvements and bug fixes:

• Link Decorators: We fixed the behavior of the multiple manual link decorators that set the rel attribute. The fix happened so deep in the engine that we improved the overall performance of the editor slightly as well.
• Added a new EmptyBlock plugin: From now on, new plugin prevents adding   to the output data of blocks, works similarly to the fillEmptyBlocks configuration in CKEditor 4.
• Support for the <hr> element in the General HTML Support plugin enhanced: attributes of the <hr> element are now properly preserved if configuration allows it.
• Emoji: We enhanced emoji support for better compatibility with users’ older devices.

For more details, see the changelog below.

# MINOR BREAKING CHANGES

• engine: The ViewConsumable.consumablesFromElement() is removed and replaced with the view.Element#_getConsumables() internal method. You should use ViewConsumable.createFrom() to create consumables if needed.
• engine: The ViewElementConsumables now accepts and outputs only normalized data. The ViewConsumable still accepts normalized or non-normalized input.
• engine: The Matcher#match() and Matcher#matchAll() output is now normalized. The MatchResult#match now contains normalized data compatible with changes in the ViewConsumable.

# Features

• engine: Export the SchemaContext class from package. Closes https://github.com/ckeditor/ckeditor5/issues/18003. (commit)
• html-support: Added support for the <hr> element. Closes #12973. (commit)
• html-support: Add the EmptyBlock plugin that prevents adding   to output data. (commit)

# Bug fixes

• collaboration-core: User initials will now be generated based on the words that start with letters, ensuring that only valid alphabetic characters are used in the initials.
• comments: Annotations will no longer be lost during real-time collaboration when a user removes and immediately reverts (undo) content containing comment markers.
• comments: The editor will no longer crash when one user removes content containing a comment that another user is editing.
• engine: The link [rel] attribute will now allow mixing manual link decorators for the same attribute, as it will be now handled as a token list. Closes #13985, Closes #6436. (commit)
• mention: Mention should not be wrapped with an additional <span> when GHS is enabled. Closes #15329. (commit)
• ui: Fixed an issue where the first selected color was applied instead of the second selected color when using the font color picker for the first time after loading the page. Closes #17069. (commit)
• typing: Removing a nested editable does not remove an entire widget when the selection is placed at the beginning of that element. (commit)

# Other changes

• clipboard: Export the viewToPlainText() function. Closes #17950. (commit)
• collaboration-core: Introduced a new configuration option: config.users.getInitialsCallback. It allows providing a custom callback function for user initials generation.
• emoji: Improved emoji support by expanding the range of versions compatible with users’ devices. Closes #18014. (commit)
• emoji: Icons representing categories in the grid come from the same Unicode version to avoid rendering the non-supported ones. (commit)
• emoji: Introduced the emoji.useCustomFont option to disable the filtering mechanism. Closes #18029. (commit)
• engine: The whitespaces around a block filler ( ) are ignored while loading editor data. (commit)

# CKEditor 5 44.2.1 release

We are happy to announce the release of CKEditor 5 v44.2.1.

During a recent internal audit, we identified a cross-site scripting (XSS) vulnerability in the CKEditor 5 real-time collaboration package (CVE-2025-25299). This vulnerability can lead to unauthorized JavaScript code execution and affects user markers, which represent users’ positions within the document.

This vulnerability affects only installations with real-time collaborative editing enabled.

You can read more details in the relevant security advisory and contact us if you have more questions.

# Bug fixes

• comments: Fixed a few scenarios for which creating a new comment thread was impossible (for example, when a selection was made on multiple table cells). This was a regression introduced in v44.2.0.

# Other changes

• real-time-collaboration: Improved displaying usernames in the user marker.

# CKEditor 5 44.2.0 release

We are happy to announce the release of CKEditor 5 v44.2.0.

# Release Highlights

# 🖥️ Enhanced Source Code Editing (⭐)

Introducing new premium feature: Enhanced Source Code Editing. It displays the source code in a dialog and is compatible with all editor types. It offers syntax highlighting, code completion, code folding, and other advanced functionalities. Additionally, it supports both HTML and Markdown formats.

# 📤 Uploadcare and image optimizer (⭐)

We have integrated the Uploadcare image manager service, enabling you to upload and edit images to their cloud environment. You can upload files from various sources, including local devices, social media, or online drives ensuring rapid uploads. The integration takes care of efficient media delivery with responsive images mechanism, making sure your users will save bandwidth and have faster website loading. You can also optimize images with the built-in image editor which offers a range of features, such as cropping, rotating, flipping, photo filters and more. All this directly from the editor, try it out!

# 🖼️ Image Merge Fields (⭐)

Image merge fields are a new type of merge fields, dedicated for image placeholders. They maintain all standard image interactions, like styling, resizing or captions (in which you can use merge fields too!) At the same time, they keep all merge fields functionalities, like data previews or document export integration. In the document data, image merge fields are represented like other images, however their src attribute is set to a respective merge field, for example, src="{{CompanyLogo}}", making them easy to post-process!

# 📝 Track Changes Preview (⭐)

We have added the preview mode that displays a document with all suggestions accepted. Accessible from the track changes dropdown, this modal preview helps check the final content without extensive markers.

# 😀 Emoji support

They are here! 🎉 🥳 🎊 Insert emojis effortlessly in the editor by typing : or through a user-friendly emoji picker. This feature enhances the richness of your content by allowing quick access to a wide range of emojis.

# ⚡ Performance improvements: Part 4

Here comes the final batch of the planned performance improvements in the editor loading speed area, that we worked on through a couple of past releases.

• A new caching mechanism in Mapper now handles model-to-view mappings, substantially improving performance for loading and saving data.
• Images with specified height and width automatically use [loading="lazy"] in the editing area, optimizing the loading time (read more on MDN). This attribute is only applied during editing to enhance the loading efficiency of images, and it does not reflect in the final data output.

We are greatly satisfied with the improved editor loading times. At the same time, we acknowledge some other problematic areas, and we will keep delivering more performance-related improvements in the future.

# MINOR BREAKING CHANGES

• engine: Mapper#registerViewToModelLength() is now deprecated and will be removed in one of the upcoming releases. This method is useful only in obscure and complex converters, where model element, or a group of model elements, are represented very differently in the view. We believe that every feature using a custom view-to-model length callback can be rewritten in a way that this mechanism is no longer necessary. Note: if this method is used, the caching mechanism for Mapper will be turned off which may degrade performance when handling big documents. Note: this method is used by the deprecated legacy lists feature. As a result, you will not experience the performance improvements if you are still using the deprecated legacy lists feature.
• image: Starting this release, images that have [height] and [width] attributes set will automatically receive the [loading="lazy"] attribute in the editing area. This happens only for the content loaded into the editor, the data output produced by the editor remains the same. The reason for this change is to improve user experience in documents that may contain hundreds of images.
• list: The lower-alpha and upper-alpha list styles are now upcasted to lower-latin and upper-latin styles.
• merge-fields: The MergeFieldsEditing#getLabel() method will now return null instead of the merge field id if the merge field definition was not found or it did not contain the label property.
• basic-styles: Elements which contains the [style] attribute with word-wrap: break-word will not be converted to <code>. See #17789.

# Features

• ai: Comment threads will now be preserved when AI Assistant processes selected content with comments. This can be disabled through the ai.aiAssistant.preserveComments flag. Note, that the actual result depends on the response provided by the AI model (AI model has to keep the comments markup in the response). Additionally, the copy-paste comments functionality must be enabled (configured by comments.copyMarkers).
• ai: The ai.aiAssistant.removeCommands configuration now allows removing entire command groups.
• ckbox: It is now allowed to specify which files chosen from CKBox are downloadable. Closes #15928. (commit)
• clipboard: Added the ability to detect paste events originating from the editor. Closes #15935. (commit)
• clipboard: Passed information to the downcast converter when clipboard pipeline is used to allow for customization. Closes #17745. (commit)
• clipboard: The viewToPlainText() helper will now parse the view RawElement instances. Closes #17746. (commit)
• emoji: Created the Emoji feature. Closes #17361. (commit)
• image: Added a possibility to break the current block by InsertImageCommand with the breakBlock flag. Closes #17742. (commit)
• list: Allowed to specify which list style types are shown in list type selector dropdown. Closes #17176. (commit)
• list: Added support for the lower-alpha and upper-alpha list type highlighting in the list style properties buttons. Closes #17424. (commit)
• mention: Allowed the mention marker to be longer than 1 character. Closes #17744. (commit)
• merge-fields: Introduced the image merge fields.
• merge-fields: Added the [data-merge-field-name] attribute in the editing pipeline.
• merge-fields: Use the actual merge field value when they are copied from the editor in preview mode other than $labels.
• source-editing-enhanced: Introduced the Enhanced Source Code Editing feature.
• table: Improve aria attributes in the table and cell align toolbars. Closes #17722. (commit)
• track-changes: Introduced the final document preview for track changes. It allows to display the document with all suggestions accepted in the modal.
• ui: The .ck-with-instant-tooltip class may now be used to display the tooltip without the delay. Closes #17743. (commit)
• upload: Added support for passing a callback to the SimpleUploadConfig#headers property. Closes #15693. (commit)
• uploadcare: Introduced the Uploadcare integration.
• utils: Added a collectStylesheets() helper function to retrieve style sheets from the provided URLs. (commit)

# Bug fixes

• ai: The content generated by the AI Assistant will now be correctly inserted into tables when both “Replace” and “Insert below” actions are used.
• basic-styles: The Code feature should not convert element with the word-wrap: break-word style into the <code> tag. Closes #17789. (commit)
• cloud-services: No longer keep refreshing token if the cloudServices.tokenUrl method failed in the initialization of the plugin. Closes #17531. (commit)
• comments: Unlinked comment threads created before the editor initialization are now correctly handled and displayed in the comments archive. This error was experienced in asynchronous integrations which are using the Context mechanism.
• comments: Do not allow editing content source via the source mode in the comments-only mode.
• comments: Introduced the name field tooltip in comments UI.
• editor-classic: Export ClassicEditorUIView from package. (commit)
• editor-inline: No longer crash while destroying the editor when the editable was manually detached before destroying. Closes #16561. (commit)
• editor-multi-root: No longer crash while destroying the editor when the editable was manually detached before destroying. Closes #16561. (commit)
• image: The insert image via URL dialog can now be submitted by pressing the Enter key. Closes #16902. (commit)
• link: Trailing punctuation is no longer included in an autolinked URL. Closes #14497. (commit)
• list: The list style buttons should show proper list type after clicking list for the first time. (commit)
• list-multi-level: Multi-level lists should work when typing in Japanese.
• merge-fields: Do not automatically convert the merge-fields-like text containing disallowed characters.
• merge-fields: Properly handle block merge fields mixed with text during data upcast and pasting.
• revision-history: The Revision history feature sidebar header height now matches the height of the editor toolbar.
• revision-history: The Revision history feature loading overlay now overlaps images correctly.
• table: Prevent a table corruption when setting editor data with <th> cells following colspan rows. Closes #17556, #17404. (commit)
• track-changes: Introduced the name field tooltip in suggestions UI.
• typing: Fixed not working two-step caret movement on iOS devices. Closes #17171. (commit)
• ui: Tooltip will no longer show after quickly hovering and moving the mouse away before the tooltip shows. Closes #16949. (commit)
• ui: Destroying another editor instance while a modal is open will no longer unlock page scroll. Closes #17585. (commit)
• utils: Extended getEnvKeystrokeText() with option to use it in the context of specified environment which allows to generate keystrokes text for different OS than the host one. (commit)
• Treat types as production dependencies. Fixes #17213. (commit)
• Unify TypeScript declaration files. Fixes #17575 and #17533. (commit)

# Other changes

• ai: Exported the AIAssistantUI class and the AIAssistantConfig, CommandDefinition and GroupDefinition types.
• clipboard: Exported the ViewDocumentPasteEvent type from the @ckeditor/ckeditor5-clipboard package. (commit)
• comments: Exported the AddCommentThreadEventData type.
• comments: Activating an annotation now scrolls to the target if it is out of view.
• comments: Fixed the wrong filter() callback signature in AnnotationsUIs#activate().
• engine: Introduced dynamic caching in Mapper to improve view-to-model mapping performance, and as a result improve editor data load and data save performance. Closes #17623. (commit)
• engine: A new parameter data was added for the change:children event fired by ViewElement and ViewDocumentFragment when their children change. The data parameter is an object with the index property, which says at which index the change happened. Related to #17623. (commit)
• engine: Mapper#registerViewToModelLength() is now deprecated and will be removed in one of upcoming releases. Note: if this method is used, the caching mechanism for Mapper will be turned off which may degrade performance when handling big documents. Note: this method is used by the deprecated legacy lists feature. See #17623. (commit)
• engine: Export SchemaCompiledItemDefinition type. Closes #17783. (commit)
• engine: Improve performance of the placeholders. (commit)
• engine: Do not store non-document operation with batches. This improves memory efficiency for huge documents. Closes #17678. (commit)
• engine: Improve performance of Selection#getSelectedBlocks when selection contains block elements with many blocks inside (such as table). Closes #17629. (commit)
• font: Export ColorSelectorDropdownView type. Closes #17783. (commit)
• image: The [loading="lazy"] attribute will be automatically added in editing view to images with the height and width attributes set to improve loading performance. (commit)
• list: Skip already visited list elements during reconversion and post fixing for better performance. Fixes #17625. (commit)
• merge-fields: The MergeFieldsEditing#refreshMergeFields() method is now public and available for external use.
• merge-fields: Remove the default values preview mode if there is none or the merge fields has a default value configured.
• merge-fields: Display ellipsis if the merge field name does not fit the dropdown.
• pagination: Do not wait for images with [width] and [height] attributes.
• pagination: Do not wait for loading images that have [width] and [height] attributes set when calculating pages.
• real-time-collaboration: Export the Sessions class.
• real-time-collaboration: Changed how errors related to real-time collaboration are handled. Previously, the original error was always logged on the console, and a realtimecollaborationclient- error was thrown without information related to the original error. Now, the original error is not logged anymore. Instead, the realtimecollaborationclient- error includes the data.originalError property with the original error message. This way it is possible to save error details through a custom error logging mechanism. Note, that without any custom mechanism, the realtimecollaborationclient- error will still be unhandled and logged to the console.
• real-time-collaboration: The editor now switches to read-only mode if the real-time collaboration client crashes, ensuring that the user cannot further edit the document and no data is accidentally lost.
• ui: Added Enhanced Source Code Editing as a default menu bar item, making it visible in the menu bar when the plugin is present in the editor. (commit)
• ui: Extended the dialog API to support custom keystroke handler options, allowing to override priorities of the keystroke callback and filter keystrokes based on arbitrary criteria. (commit)
• ui: The ImageInsertUI#registerIntegration method now supports handling an array of views for a specific integration type. This allows, for example, registering an assetManager integration with multiple sources like Facebook and Instagram, where each source has its own dedicated button. (commit)
• ui: Exported the DocumentColorCollection class. Closes #17783. (commit)
• utils: Extended key codes with the End and Home keys, enabling the use and display of shortcuts containing these keys in the UI. (commit)
• utils: Exported the add() function. Closes #17783. (commit)