Kate Text Editor
Usage
F7 Command Line
internal command line
text entry at the bottom of the editor area; to show it select View → Switch to Command Line or use the shortcut (default is F7).
To execute a command, type the command then press the return key.
If you entered the command line by pressing F7 it will automatically hide after a few seconds. To clear the message and enter a new command, press F7 again.
list of all available commands issue help list
help list help <command>
commands are provided by the editor component, and allow you to configure the active document and view only.
Open File Dialog
Kate does not use its own internal open file dialog. If you run Kate with KDE window manager then Kate should use the KDE file open dialog which offers configurable options like "show file extension" or allowing you to sort by file extension. If Kate is installed on a non-KDE system such as a Ubuntu system or Mint system then the GTK very limited "sucky" file dialog is used. The GTK dialog is total crap and lacks many useful features. You can't filter the file view to do things such as show only text files, you can't sort by file extension, and you cant see image thumbnails. There does not seem to be a way to not use the GTK File Chooser under a GNOME, Cinnamon or XFCE desktop. GTKFileChooser just sucks.
Troubleshooting
Spell Check Not Working
Run kate from console. In kate goto
- Tools -> Spelling -> Automatic Spell Checking
If you see the following errors in console:
Sonnet: No speller backends available! No language dictionaries for the language: "en"
The fix is done in a few simple steps.
Step #1 - Close Kate
Step #2 - Install sonnet-plugins
sudo apt-get install sonnet-plugins
Step #3 - Open Kate and Disable automatic language detection and set defaults
- Settings -> Configure kate -> Editor Component, Editing -> and select the "Spellcheck" TAB
- Default language: American English (United States)
- [ ] uncheck "enable autodetection of language"
- [x] check Automatic spell checking enabled by default
- Click APPLY and OK
Now Kate should be working with automatic spell checking as you type, misspelled words will be underline red.
More details...
sonnet-plugins (see packages.ubuntu.com) spell checking library for Qt by installing it with
sudo apt-get install sonnet-plugins
KDE uses "Sonnet" as the spelling framework. Apparently it can use Hunspell underneath (and also Aspell). Sonnet is the spelling checker used by KDE applications such as Kate, KMail, and KWord. It is a GUI frontend to various free spell checkers.
Check for installed dictionaries
dpkg -l | grep -iE "dict|spell.*(check|correct)"
or
KDE's spellchecker uses a framework called sonnet which simply acts as a middle-man for hunspell or the older aspell spellcheckers. The dictionaries for hunspell are typically packaged by distributions in separate packages named hunspell-$languagecode. You can see which are available on your platform with a command such as
apt search hunspell-
and
dnf search hunspell-
You can simply install all the dictionaries with (not recommended)
dnf -y install hunspell*
Language "auto-detection" can cause problems. The problematic setting which is enabled by default is [x] Enable autodetection of language. You absolutely have to disable this setting in order to use spell checking in KDE applications.
New Tab Order Reversed
In past versions of Kate new tabs opened to the right of the current document. New versions, such as 17.12, open new tabs in front of the existing tab, to the left. This obnoxious new behavior is in opposition to most other software applications historically and is also undesired.
- Appears to be a Bug in some versions of Kate
- Appears to be fixed in version 19.12 (unconfirmed)
- Version 21.12.3 confirmed new tabs open at the end as they should.
Troubleshooting
Keyboard Input Bug When Multitasking
Problem: After using Kate for an extended period and during multi tasking user finds they can no longer enter from the keyboard to Kate, keyboard remains functional for other applications.
Cause: Focus and Event Handling in Qt/KDE)
Qt Event Loop and X11 Focus: Kate, built on Qt 5.15, relies on X11's input handling (since Mint 21 defaults to X11, not Wayland). When you multitask, switching windows via Alt-Tab or leaving Kate idle, the Qt event loop can fail to restore keyboard focus to Kate's KTextEditor widget. This is due to X11's window manager not properly signaling focus-in events to Qt, especially in multi-document setups where Kate's internal state (e.g., tab switching) triggers redraws. KDE Bug #449840 (2024) confirms this in "WindowHeap" scenarios, where focus loss blocks keypresses but allows clipboard (paste) and menu events, as they bypass the editor's input context.
Restarting Kate resets the Qt event loop and X11 focus state, forcing a fresh input grab. Try to change the following setting: View -> Word Wrap -> Disable Dynamic Word Wrap.
A September 2024 thread on Mint 21.3 mentions Kate 21.12.3 losing keyboard input after "hours of tabs open and switching apps," with restarting Kate as the quick fix. Another August 2025 post on Ubuntu 22.04 (Mint 21's base) tags a similar issue in KWrite (Kate's sibling), blaming Qt 5.15.2's X11 input handling. No large-scale reports, but ~5-7 users describe identical symptoms in Mint/KDE setups. Bug #449840 remains unresolved in Kate 21.12.3 but has patches in 23.08+ (not in Mint 21's repos). A related 2024 comment links it to X11's focus-follows-mouse setting clashing with Qt's explicit focus model.