Improvements - Avoid unnecessary scroll after inserting a snippet when the range is already visible. - Update the Markdown syntax to improve headings highlight. - Update tree-sitter-scala to 0.26.2. Fixes - Fix an issue in the regular expression replacement with the “Unescape replacement text” option where escaped backslashes in the replacement string were unexpectedly removed instead of being unescaped to literal backslashes. - Fix an issue in the LaTeX syntax where custom environment definitions were incorrectly extracted as outline items. - Fix an issue in the LaTeX syntax where the opening braces of arguments of some commands, such as `\cite`, were highlighted in the wrong color. - Fix an issue in the Scala syntax where string interpolators, such as `s` in `s"…"`, were highlighted in the same color as the string body. - Fix typos in Dutch and French localizations.

Improvements - Prevent the file browser from opening UNIX executable files as plain text. - Display more accurate error messages in dialogs. - Updated the SON syntax to change the file mapping for `Package.resolved` from file extensions to filenames. - Improve cancellation handling for syntax highlighting with computationally intensive regular expressions. - Improve localization. - Improve overall stability. Fixes - Fix an issue where the application could crash or freeze when undoing an edit that shortened the document, such as the trimming of trailing whitespace. - Fix an issue where the tab width customized for a document was not applied when printing. - Fix an issue where the insertion point could move to an incorrect column when extending a selection upward from the end of the document. - Fix an issue where the Surround Selection With > Custom dialog did not show the last used strings. - Fix an issue where the window size setting was not included in the exported settings archive. - Fix an issue where the incompatible character list in the Warnings inspector was not updated when the document’s text encoding was changed.

Improvements - Improve the performance of saving a large document encoded in Western (ASCII). - Improve overall stability and performance. Fixes - Fix an issue where changes to the “Make file executable” option in a canceled save panel could be applied to a subsequent save. - Fix an issue where the app became unresponsive when a document was automatically updated due to an external modification while an alert for the document was displayed. - Fix an issue where the alerts about inconsistent line endings or an external modification could be displayed twice for the same document. - Fix an issue where text typed in an untitled document while another document was being opened could be lost without warning. - Fix an issue in the file browser where the “Open in New Window” command did not work for the file currently displayed as a preview. - Fix an issue where the Syntax toolbar menu was no longer updated once the toolbar customization dialog was opened. - Fix an issue where wrapped lines could be printed with an incorrect indentation width when hanging indentation was enabled. - Fix several issues in editing commands with multiple cursors or selections. - Fix an issue where the “Shift Left” command could crash the app when the selection started within the indentation. - Fix an issue where the app could crash when selecting a completion candidate in the Touch Bar. - Fix an issue where the app could become unresponsive when modifying the selection word by word in text containing combining characters. - Fix an issue where setting the tab width to zero with AppleScript could crash the app. - Fix an issue where the automatic outdent when typing a closing symbol, such as “}”, removed only a single character instead of a whole indent level in space-indented documents when the tab character is preferred for indentation. - Fix an issue where the “URL Encode” command could fail for selections containing an invalid percent-encoding sequence, such as a standalone “%”. - Fix an issue where expanding the selection to the beginning of the line discarded the selected range ahead of the anchor when the selection was made from left to right. - Fix several issues in modifying the selection in documents containing inconsistent CRLF line endings. - Fix an issue where the insertion point could move to an unexpected position after typing a quotation mark when the Smart Quotes substitution is enabled. - Fix the Portuguese localization.

Fixes - Fix an issue on CotEditor 7.0.5 where documents without a filename extension could not be saved due to a false permission error when a syntax with associated filename extensions is applied. - Fix an issue where the external modification alert could wrongly appear on saving a document in a synced folder even when the file content was unchanged. - Fix an issue where typing a closing quotation mark just before an automatically inserted closing quotation mark could insert an extra pair of quotation marks instead of just moving the insertion point. - Fix an issue where the Find window could unexpectedly resize while dragging the divider of the find result view.

New Features - Add the Services menu to the context menu of the file browser. Improvements - Avoid reopening the completion list automatically after typing an additional character during manual completion. - Update tree-sitter-swift to 0.7.3. - Fine-tune the layout for the new macOS. Fixes - Fix an issue where the Command-Left Arrow command could fail to move the cursor to the beginning of the current wrapped visual line. - Fix an issue on macOS 26.5.1 where the “Suggest completions while typing” option could unexpectedly commit text being composed. - Fix an issue where the text composing in a text field on the Find window could disappear while incremental search. - Fix an issue where regular-expression syntax highlighting in input fields could fail to update immediately when changing regular expression mode while editing. - Fix an issue where the Advanced Character Counter could sometimes be positioned incorrectly. - Address an issue where the external modification alert could appear after saving a document in a synced folder.

Improvements - Improve VoiceOver support by letting the editor read the text count information shown in the status bar with VO-Shift-H. - Improve the paired-symbol matching algorithm for brackets and quotation marks. - Remove the Rich Text Format built-in syntax. Fixes - Fix an issue where saving a file could drop special POSIX permission bits, such as `setuid`, `setgid`, or `sticky`. - Fix an issue where moving the cursor near leading invisible characters could crash the application. - Fix an issue where copying or moving a file with certain filenames could unexpectedly change the filename while avoiding a conflict. - Fix an issue where the incompatible character list in the Warnings inspector could miss some characters that change after text encoding conversion. - Fix an issue where block comment delimiters could be inserted at the wrong indentation when commenting out lines with mixed indentation. - Fix an issue where NFKC Case-Fold normalization could leave default-ignorable Unicode characters in the text. - Fix an issue where invisible character symbols could be drawn incorrectly in right-to-left text. - Fix an issue where replacing an existing setting during import could fail for certain files. - Fix an issue on macOS 15 where the Export command in the Format settings pane’s menu could fail to export a syntax. - Fix typos in German localization.

New Features - Add the Ada syntax. Improvements - Add CSS HWB and 4-digit hexadecimal alpha formats to the Edit Color Code command, and allow it to read modern space-separated CSS RGB/HSL color codes. - Support spaces between menu path components in Quick Actions search. - Support shebangs with options for syntax detection. - Improve line sorting commands to better preserve existing mixed line endings. - Limit tree-sitter-based syntax highlighting to 100,000,000 characters to avoid unexpected crashes. - Update the Markdown syntax to fix highlighting block quotes. - Update the Unicode block name list for the character inspector from Unicode 16.0.0 to Unicode 17.0.0. - Update tree-sitter-c to 0.24.2. - Update tree-sitter-swift to 0.7.2. - Improve overall stability and performance. Fixes - Fix an issue where customized built-in syntaxes could be ignored when their file mappings conflicted with other built-in syntaxes. - Fix an issue where text near the end of a very large document could fail to appear when hanging indentation was enabled. - Fix an issue where text following an emoji tag sequence could be rendered as missing glyphs. - Fix an issue where deleting by word or to the beginning of a line could delete text outside the selection. - Fix an issue where selecting a word could select an incorrect range. - Fix an issue where Sort by Pattern could reorder lines that do not contain the specified sort key. - Fix an issue where dropping text clippings or File Drop snippets could insert extra text when their line endings differed from the document’s. - Fix an issue where File Drop snippets could omit the domain from dropped web URLs. - Fix an issue where the Restore Defaults button in File Drop settings could remain disabled even when the current settings differed from the defaults. - Fix an issue where opening multiple documents at once could open them in separate windows even when window tabbing was set to Automatically. - Fix an issue where opening multiple documents while an empty untitled document was open could show some documents before replacing the empty document. - Fix an issue where canceling or failing to open a document could leave an empty untitled document behind. - Fix an issue where text encoding and read-only options in the Open dialog could be unavailable when selecting files together with folders. - Fix an issue where syntax-specific snippets and scripts could remain scoped to the previous document after switching documents in the file browser. - Fix an issue where the Document inspector could keep showing the previous document path after closing a document in the file browser. - Fix an issue where opening the original folder of an alias from the file browser could fail after requesting file access permission. - Fix an issue where opening a UTF-16 or UTF-32 document with a BOM using a byte-order-specific encoding could leave the BOM in the document text. - Fix an issue where converting a document to a non-UTF-8 encoding with AppleScript’s BOM option could add an invalid UTF-8 BOM. - Fix an issue where encoding detection could prioritize a later encoding declaration over the first one found in the document. - Fix an issue where custom syntax highlighting could crash when a begin/end regular expression matched zero-length text at the end of the document. - Fix an issue where an unterminated begin/end string pattern could prevent later custom syntax highlighting from being applied. - Fix an issue where a malformed custom syntax definition with empty delimiters or empty highlight patterns could make syntax highlighting hang. - Fix an issue where tree-sitter-based syntax highlighting could become misaligned after editing around consecutive empty lines or a trailing line ending. - Fix an issue where importing settings could incorrectly show an error for a custom theme included in the same settings archive. - Fix other minor issues.

Improvements - Improve reliability when UNIX scripts process large input or output through pipes. - Allow AppleScript encoding conversion to use encodings outside the customized encoding list. - Improve responsiveness when performing the Select All Find Matches command in large documents. - Close open documents in the file browser when their containing folder is moved to the Trash. Fixes - Fix an issue in CotEditor 7.0.1 where saving an extensionless document could leave it treated as locked by the system (`com.apple.provenance` extended attribute), preventing later overwrites. - Fix an issue where deleting forward with multiple cursors could crash when an insertion point was at the end of the document. - Fix an issue where pasting text copied from multiple selections in a CRLF document could insert incorrect text. - Fix an issue where the Sort by Pattern command could insert extra blank lines in CRLF documents. - Fix an issue where specifying an out-of-range negative line range could crash. - Fix an issue where highlights for instances of selected text could reappear after turning the option off. - Fix an issue where a failed script could leave its name in subsequent console messages. - Fix an issue where print settings specified by AppleScript could be ignored. - Fix an issue where edits in the Multiple Replace window could be lost after immediately selecting, renaming, or deleting definitions. - Fix an issue where Replace All and Multiple Replace could fail to apply replacements between Unicode-equivalent strings, such as `·` (U+00B7) and `·` (U+0387). - Fix an issue where performing Find All or Highlight All in a read-only document could make the document editable. - Fix an issue where regular expression search could get stuck at the same position when matching zero-length text. - Fix an issue where regular expression syntax highlighting could be applied incorrectly. - Fix an issue where custom keyboard shortcuts using the Forward Delete key could not work. - Fix an issue where document open/save scripts could fail to run immediately after launch or script folder changes. - Fix an issue where the default text encoding could be removed from the Encoding List. - Fix an issue where detecting encoding-incompatible characters could miss Unicode-normalized text changes. - Fix an issue where syntax definition files with reserved names could be imported and appear as unusable custom syntaxes. - Fix an issue where changes to Mode settings might not take effect immediately. - Fix an issue where changing the document appearance or deleting a custom theme could leave the theme editor in the Appearance settings pane showing an outdated theme. - Fix an issue in the file browser where renaming an item while filtering could show stale results or crash. - Fix an issue in the file browser where moving both a folder and its contained items to the Trash at the same time could show an incorrect confirmation or unnecessary error. - Fix an issue in the file browser where old filter results could be shown after changing the filter text quickly.

Improvements - Improve outline extraction algorithm for the LaTeX and Swift syntaxes. - Update the Markdown syntax to highlight some FrontMatter format. Fixes - Fix an issue where the default filename extension in the Save dialog didn’t reflect the current syntax. - Fix an issue where CotEditor Syntax (.cotsyntax) files could not be imported from the Format settings. - Fix an issue where the options selected in the Open dialog might not be applied to all documents when opening multiple documents at once. - Fix an issue in the cot command where the --wait option could fail to return focus to the client terminal in some terminal apps.

Compatibility Changes - Introduce CotEditor Syntax, a new syntax definition format. The legacy YAML-based syntax definition format is now deprecated, and user-created syntaxes are automatically migrated on first launch. New Features - Adopt smarter syntax parsing powered by tree-sitter for multiple built-in syntaxes, improving syntax highlighting and outline extraction in C, C#, C++, CSS, Go, HTML, Java, JavaScript, Kotlin, LaTeX, Lua, Makefile, Markdown (outline extraction only), PHP, Python, Ruby, Rust, Scala, Shell Script, SQL, Swift, and TypeScript. - Display symbolic icons next to outline items. - Allow collapsing outline items in the Outline inspector for tree-sitter-based and structured document syntaxes. - Add the “Wrap Lines” option to the Outline inspector. - Make smart indentation aware of the current syntax. - Expand comment delimiter settings in syntax definitions, allowing multiple delimiters and related options. - Add detailed delimiter settings for strings, characters, and indentation to syntax definitions. - Add the Multiline option to highlighting rules in syntax definitions so matches can span multiple lines. - Show the current position in search results in the Find field while navigating between matches, for example, “2/5”. - Add CurrentLine and ReplaceCurrentLine to the UNIX script input/output keywords for editing the current line in the editor. - Add Bulgarian localization. Improvements - Update the inspector’s appearance on macOS Tahoe 26. - Improve the syntax-highlighting algorithm for legacy regex-based parsing. - Update built-in syntaxes. - Use the user’s window size setting for the Zoom action, if available. - Improve word selection and related editing actions to treat commas as word delimiters. - Improve general text-editing performance. - Hide line numbers in the window titlebar area when the navigation bar is hidden on macOS Tahoe 26. Fixes - Fix incorrect syntax parsing in some built-in syntaxes. - Fix an issue where the default file extension in the Save dialog was .txt for syntaxes with a file extension not registered in the system. - Fix an issue where TSV multiple replace definitions could fail to overwrite an existing definition when re-imported. - Fix an issue where TSV multiple replace definitions could not import empty replacement strings. - Fix an issue where key bindings imported from a settings archive could be lost after relaunching the app. - Fix issues in the file browser where items could point to the wrong location after being moved or renamed. - Fix an issue in the file browser where replacing a file with a folder, or vice versa, could leave the displayed state outdated. - Fix an issue in the file browser where newly created or duplicated items could fail to become selected immediately in some folders. - Fix issues where the Script menu could become outdated after changes in the Scripts folder. - Fix an issue where line reordering commands could insert extra blank lines in documents using CRLF line endings. - Fix an issue where AppleScript could return an unclear error when a folder document had no current document. - Fix an issue where requesting a zero-length text range via AppleScript could return an unintended character. - Fix an issue where some decimal setting values could use the wrong number format and be reset unexpectedly in certain locale configurations.

Improvements - Improve stability on MacBook Pro models with Touch Bar. Fixes - Fix a crash on exporting settings when some setting values are not customized. - Fix a potential crash in Find All when a matched line is extremely long. - Address a potential crash when editing a keyboard shortcut in the snippets settings.

Improvements - Create a new document from a UNIX script only when output is available, using the %%%{CotEditorXOutput=NewDocument}%%% option. - Improve overall stability. Fixes - Fix an issue where the default file extension for Markdown documents was .txt instead of .md. - Fix an issue where snippets were not included in the settings export. - Fix an issue where settings imported from a settings archive incorrectly included filename extensions. - Fix an issue where invisible characters were not printed even if the “Print Invisible” option in the print settings was enabled. - Fix descriptions in the user guide for UNIX scripting. - Address a potential crash in the file browser when creating, duplicating, or moving files. - Address a potential crash when a document was modified by another process.

Fixes - Fix an issue where smart indentation did not work under certain conditions. - Fix an issue in the Find window where syntax highlighting for regular expressions could break for some patterns. - Fix an issue where the editor incorrectly highlighted paired symbols when an escaped symbol was nearby. - Fix an issue in the file browser where TypeScript documents were incorrectly displayed with a video icon. - Address a potential crash when pasting multiline text into the editor under certain conditions. - Address a potential crash when closing a document.

New Features - Add AppleScript support for `folder document`, including the `current document` property and forwarding of `document` commands. Improvements - Optimize the performance of scanning incompatible characters. - Accept the JSON5 format when importing custom themes and multiple replace definitions. - Improve the behavior of trailing whitespace trimming. - Update the JSON syntax to highlight comments in the JSON5 format. - Improve overall stability. Fixes - Fix an issue where the app could crash when opening a large file while the Warnings inspector was open. - Address an issue where the Save dialog for documents ignored the current syntax for the default file extension.

New Features - Add the `--goto` option to the `cot` command-line tool as syntactic sugar for the `--line` and `--column` options. See `--help` or the user guide for details. - Add Chinese (Hong Kong) localization. Improvements - Improve the text encoding detection algorithm. - Update the C++ syntax to include the .cu and .cuh filename extensions. Fixes - Fix an issue in the syntax editor where the outline title field occasionally became uneditable. - Fix an issue in the Outline inspector where matches filtered by the filter field were not highlighted. - Update the Swift syntax to fix outline extraction.

Improvements - Improve word deletion to treat periods and colons as word delimiters. - Update the filter after duplicating a file in the file browser. - Update the user guide. Fixes - Fix an issue in the file browser where files weren’t hidden when the document’s folder name matched the filter string. - Fix an issue where the app crashed when cutting rectangular selections at the end of a document with CRLF line endings.

New Features - Add a feature to export and import settings to transfer them to another Mac. - Allow opening alias and symlink documents from the file browser. - Request file access permission from the user by the “Open in New Window” command instead of simply presenting an error when CotEditor doesn’t have permission. - Display the original path for alias and symlink files in file preview views. - Support for importing multiple replace definitions from tab-separated values. Improvements - Syntax highlighting now takes nesting into account when highlighting symbol pairs. - Update the Lua syntax to support nested string delimiters. - Update the contents and layout of the user guide. Fixes - Fix an issue in CotEditor 6.1.2 where the text entered in a split editor didn’t match the theme's text color. - Fix an issue where the default syntax setting reverted to Plain Text after a short time when set to None. - Fix an issue where scroll bars in the editor became invisible under certain theme and appearance combinations. - Fix an issue in the Donation settings pane where the purchase button for the one-time donation didn’t work on subsequent attempts. - Address an issue where scrolling the editor with arrow keys caused unexpected jumps.

Improvements - Keep the selection in the file browser when filtering by filename. Fixes - Fix an issue where changing the theme color while a document is in front of the Settings window immediately overwrites the editor’s text color with the selected color. - Fix an issue where an incremental search with the global search text is automatically performed when the application becomes active. - Fix an issue where the file browser prompts an error message when selecting a symlink or alias whose original is unavailable.

Improvements - Reset filename filtering by performing the Add File/Folder commands. Fixes - Fix an issue where the editor doesn’t receive focus by document opening when the system keyboard navigation feature is enabled. - Fix an issue where a focus ring appears in an empty area in the navigation bar by document opening when the system keyboard navigation feature is enabled. - Fix an issue in the file browser where the the items are not sorted when a top-level item was renamed. - Fix an issue in the Quick Action bar where the last input remains. - Fix an issue in editors where the word selection doesn’t expand properly when dragging the mouse.

New Features - Introduce the filter feature in the file browser. - Introduce the “Insert comment delimiters after indent” option to the Edit settings pane. - Revert the “Append a space to comment delimiter” option to the Edit settings pane. - Add Russian localization. Improvements - Improve the algorithm to comment out block comments. - Ignore .git folders in the file browser. - Prevent moving focus to the editor when selecting a document in the file browser. - Update the Verilog syntax to support SystemVerilog. - Update the Swift syntax. Fixes - Fix an issue where the counts in the status bar are occasionally unavailable when the document is opened. - Fix an issue where the text fields in sheet dialogs don’t get focus when they appear.

Improvements - Improve the user interface details on macOS 26. - Enable the enhanced runtime security protections. - Ensure that the sidebar is always displayed when opening a folder document. - Improve the “Open with External Editor” button in file preview views to allow specifying the application to open. Fixes - Workaround an issue on macOS 26 where the editor’s scroller tracks have a different style compared to standard scrollers. - Fix an issue where the counts in the status bar are occasionally unavailable when the document is opened. - Fix an issue in the vertical text orientation where the line number view is tucked beneath the titlebar when the navigation bar is hidden. - Fix an issue in the multiple replacement window where the text selection is unexpectedly canceled. - Fix an issue where the editor in a document opened by replacing with a blank document doesn’t initially have focus. - Fix an issue in the Find All command where the result view doesn’t display the correct document title when the target document was created by replacing with a blank document. - Fix an issue where the line endings pop-up button doesn’t work when the document was opened in a blank document. - Fix an issue in the multiple replacement window where the sidebar can be collapsed. - Fix an issue where the syntax mapping conflict view cannot be closed.

Improvements - Change the default editor font size to 13 pt. Fixes - Fix an issue on macOS 15 where the horizontal scroller appears in editors even when setting lines to wrap. - Address a potential crash on macOS 26 that can occur when opening a document. What’s New in Version 6.0.2 Fixes - Fix an issue on macOS 26 where the application crashes by opening the Donation settings pane while a system theme color other than Multicolor is selected in the System Settings > Appearance. - Fix an issue where the theme setting changes unexpectedly when opening the Appearance settings pane after switching the system appearance mode. - Fix an issue where the indentation style detection doesn’t work.

Fixes - Fix an issue on macOS 26 where the application crashes by opening the Donation settings pane while a system theme color other than Multicolor is selected in the System Settings > Appearance. - Fix an issue where the theme setting changes unexpectedly when opening the Appearance settings pane after switching the system appearance mode. - Fix an issue where the indentation style detection doesn’t work.

Improvements - Avoid assigning the Shift+Return shortcut key for a snippet. Fixes - Fix an issue where the file browser doesn't show the entire filenames when the scroller slot is shown. - Fix an issue where the “Convert Indentation” commands don’t convert if no characters are selected. - Fix an issue where the input fields in the Find window accept rich text. - Fix an issue where folder documents can open multiple windows for the same folder. - Address a potential crash on macOS 26 that occurs when performing a keyboard shortcut. - Address a potential crash on macOS 26 that can occur when opening a document on an Intel-based Mac.

New Features - Support macOS Tahoe 26. Improvements - Change the system requirement to macOS Sequoia 15 and later. - Update the user interface on macOS 26 to the Liquid Glass style. - Update the application icon to the Liquid Glass style. - The options to highlight matching braces have been removed and they are now always highlighted. - Apply the text find highlighting to all split editors. - Move selected items to the Trash by the Delete action in the file browser. - Show also the file size of the previewed document in the status bar. - Display the numbers of registered items below the lists in the syntax editor. - Deprecate the feature to change the editor opacity per window. - Deprecate the feature of installing a custom theme by simply opening the file in CotEditor. - Deprecate the “Make Snake Case,” “Make Camel Case,” “Make Pascal Case,” “Hiragana to Katakana,” and “Katakana to Hiragana” commands in the Text > Transformations menu. - Deprecate the “Draw separator” option for the line number view on macOS 26. Fixes - Fix an issue where the “Convert Indentation” commands don’t convert indentation to the indent style that’s not the default. - Fix an issue where the Syntax toolbar menu is disabled when the toolbar is shown afterward. - Fix an issue where the size of the Multiple Replace window is not stored. - Fix an issue in the Dutch localization where the number of found items isn’t displayed in the Find window.