Desktop Entry Parameters and What the Desktop Does With Them

This document is the operational reference for every key a *.desktop file may carry. It records what each key does, which desktop component consumes it, and how to inspect the effective value.

documents/08-desktop-entry-format.md defines the file format and the parser rules. This document defines the meaning and the effect. Live-state facts were verified 2026-09-21 on this Ubuntu 24.04 GNOME Shell 46.0 host.

Sources

Desktop Entry Specification version 1.5: https://specifications.freedesktop.org/desktop-entry-spec/latest/
Desktop Menu Specification: https://specifications.freedesktop.org/menu-spec/latest/
Icon Theme Specification: https://specifications.freedesktop.org/icon-theme-spec/latest/
MIME Applications Specification: https://specifications.freedesktop.org/mime-apps-spec/latest/
AppImage desktop integration keys: https://docs.appimage.org/reference/desktop-integration.html
AppImageLauncher X-AppImage-* keys: https://github.com/TheAssassin/AppImageLauncher

Components That Consume a Desktop Entry

Component	Reads	Effect
Application menu (GNOME Shell, `gmenu`)	`Name`, `Icon`, `Categories`, `NoDisplay`, `Hidden`, `OnlyShowIn`, `NotShowIn`	the entry appears, is grouped, or is hidden
Launcher (`gio launch`, `gtk-launch`)	`Exec`, `TryExec`, `Path`, `Terminal`, `DBusActivatable`	the application starts
Dock and window tracker	`StartupWMClass`, `StartupNotify`	the window is matched to the launcher and shows its icon
File manager and MIME database	`MimeType`, `Exec` field codes	the application is offered for a file type
Launcher context menu	`Actions` plus `[Desktop Action ...]` groups	extra commands are offered
Icon loader	`Icon`	an icon name or absolute path is resolved

Core Identity Keys

Key	Type	Required	Meaning and effect
`Type`	string	yes	`Application`, `Link`, or `Directory`; determines which other keys are legal
`Version`	string	no	the specification version the entry conforms to, `1.5` today; ignored by most desktops
`Name`	localestring	yes	the label in the menu and dock; `--name` overrides it, so several launchers for one application can be told apart by version
`GenericName`	localestring	no	a category label such as `Web Browser`
`Comment`	localestring	no	the tooltip
`Keywords`	localestring(s)	no	extra search terms; a semicolon list
`Categories`	string(s)	no	menu placement, from the registered category list; one main category is recommended
`Icon`	iconstring	no	an icon name resolved through the icon theme, or an absolute path
`NoDisplay`	boolean	no	`true` keeps the entry out of menus while it stays usable for file associations

Notes:

Categories is validated by desktop-file-validate, which warns when more than one main category is present because the application may then appear twice.
Icon with an absolute path bypasses theming and scaling, and breaks if the file moves; a name installed under hicolor is the durable form.
Name and GenericName and Comment may carry locale postfixes such as Name[de].

Visibility Keys

Key	Type	Meaning and effect
`Hidden`	boolean	`true` means “deleted for this user”; equivalent to the file not existing
`OnlyShowIn`	string(s)	show only in the listed desktop environments
`NotShowIn`	string(s)	hide in the listed desktop environments

Matching is against the colon-separated $XDG_CURRENT_DESKTOP value, for example ubuntu:GNOME. When OnlyShowIn is present the default becomes “do not show”.

Launch Keys

Key	Type	Required	Meaning and effect
`Exec`	string	yes unless `DBusActivatable=true`	the command line to run
`TryExec`	string	no	if this executable is missing, the entry is treated as absent and hidden
`Path`	string	no	the working directory for the launched program
`Terminal`	boolean	no	`true` launches the program inside a terminal emulator
`DBusActivatable`	boolean	no	`true` activates the application over D-Bus instead of `Exec`
`StartupNotify`	boolean	no	`true` asks the desktop to show a starting indicator
`StartupWMClass`	string	no	the window class that belongs to this launcher
`PrefersNonDefaultGPU`	boolean	no	prefer a non-default GPU on dual-GPU systems
`SingleMainWindow`	boolean	no	the application can only have one main window

Notes:

Exec is the key that integration must rewrite, because the embedded value usually names a program inside the payload rather than the AppImage itself.
TryExec is the key that makes a stale launcher disappear instead of appearing broken.
StartupWMClass is what makes the dock show the right icon for a running AppImage; without it the window is anonymous. The embedded value is the AppImage author’s guess, so it can disagree with the class the application actually reports: read the real one with appimage-integrate windows and set it with --wm-class, which then outranks the embedded entry.
Path inside an AppImage is usually wrong, because the working directory should be the mount point or the AppImage’s own directory.

Exec Field Codes

Code	Expands to
`%f`	a single file path
`%F`	a list of file paths
`%u`	a single URL
`%U`	a list of URLs
`%i`	the icon as two arguments, `--icon` and the `Icon` value
`%c`	the translated `Name`
`%k`	the path of the desktop file itself

Rules:

A literal percent sign is %%.
Deprecated and ignored: %m, %v, %d, %D, %n, %N.
Field codes are expanded once; expanded text is not rescanned.
An unlisted field code makes the command line invalid and it must not be processed.
Arguments containing spaces, quotes, or other reserved characters are quoted with double quotes; ", `, $, and \ are escaped with a backslash.
For an AppImage, the whole absolute AppImage path is quoted and followed by the entry’s own field code.

Association Keys

Key	Type	Meaning and effect
`MimeType`	string(s)	the MIME types the application can open

The list is a semicolon-separated set, for example model/stl;application/x-amf;.
A MIME type becomes openable by this application only when the entry is visible to the MIME database; update-desktop-database refreshes the cache in each applications directory.
The default application for a MIME type is recorded separately in mimeapps.list, not in the desktop entry.

Action Keys

Key	Type	Meaning and effect
`Actions`	string(s)	identifiers of additional commands offered in the launcher context menu

Each identifier has a group [Desktop Action <identifier>] containing:

Key	Type	Required	Meaning
`Name`	localestring	yes	the context-menu label
`Exec`	string	yes unless D-Bus activated	the command to run
`Icon`	iconstring	no	the context-menu icon

AppImageLauncher uses actions for its lifecycle:

Actions=AppImageLauncher-Remove-AppImage;AppImageLauncher-Update-AppImage;
    [Desktop Action AppImageLauncher-Remove-AppImage]
    Name=Delete this AppImage
    Exec=/path/to/remove "%f"

Compatibility Keys

Key	Type	Meaning and effect
`Implements`	string(s)	interfaces the application implements, such as `org.freedesktop.FileManager1`
`URL`	string	required for `Type=Link`

Extension and Provenance Keys

Keys beginning with X- are extensions and are ignored by desktops that do not know them. They are the correct place to record provenance.

Key	Defined by	Meaning
`X-AppImage-Name`	AppImage	application name, used to relate versions
`X-AppImage-Version`	AppImage	bundled application version
`X-AppImage-Arch`	AppImage	bundled architecture
`X-AppImage-Identifier`	AppImageLauncher	hash identifying the AppImage file
`X-AppImage-Old-Icon`	AppImageLauncher	the icon name the entry was created with
`X-AppImageLauncher-Version`	AppImageLauncher	the version of the tool that wrote the entry
`X-GNOME-FullName`	GNOME	historical full name
`X-GNOME-Autostart-*`	GNOME	autostart condition and delay
`X-KDE-*`	KDE	KDE-specific behavior
`X-AppInstall-Package`	appstream	the distribution package the entry was generated from

Deprecated Keys

These are recognized but should not be produced.

Encoding, MiniIcon, TerminalOptions, Protocols, Extensions, BinaryPattern, MapNotify, SwallowTitle, SwallowExec, SortOrder, FilePattern, Dev, FSType, MountPoint, ReadOnly, UnmountIcon, ServiceTypes, DocPath, InitialPreference.

Historical values that readers must still accept:

Boolean 0 and 1 for false and true.
Comma-separated lists before specification 1.0.
The [KDE Desktop Entry] group name and the .kdelnk extension.

How to Inspect Every Parameter

Question	Command
What does this file literally say?	`desktop-inspect FILE`
What value does a locale actually get?	`desktop-inspect --locale de FILE`
Which entry wins for an identifier, and what does it mask?	`desktop-inspect --explain ID`
What are the valid values for a field?	`desktop-file-validate FILE`
Which entry does the menu use for this identifier?	`gio launch ID`, or `gtk-launch ID`
What icon does a name resolve to?	`desktop-inspect --icon NAME`
Which application opens a MIME type, and from which file?	`desktop-inspect --mime TYPE`
What are all the parameters in the wild on this host?	`desktop-inspect --all --fields`

Verification

Key meanings: verified 2026-09-21 against Desktop Entry Specification version 1.5.
Field codes: verified 2026-09-21 against the specification’s Exec key section.
AppImage keys: verified 2026-09-21 against the AppImage desktop-integration documentation and this host’s AppImageLauncher-generated entries.
Component behavior: verified 2026-09-21 on GNOME Shell 46.0.