Windows Sound Mixer

A per-application volume mixer for Windows. Adjust the volume of any running program with an audio session (or the system master volume) from a small always-on-top overlay, the system tray, or global hotkeys.

Sound Mixer overlay demo

Run, Build, Test details

Install via WinGet

Sound Mixer is available on WinGet as GetItSimple.SoundMixer:

winget install --id GetItSimple.SoundMixer --exact --source winget

Running from source

pip install -r requirements.txt
python -m sound_mixer

Building a standalone executable

python build.py

build.py checks that all packages in requirements.txt are installed at the required versions. If anything is missing or outdated, it lists the packages and asks whether to install them with pip before continuing. It then runs PyInstaller and produces dist/SoundMixer.exe.

Building the NSIS installers

NSIS 3.12 is required. Build the application first, then compile both x64 installer scopes with warnings treated as errors:

python build.py
./scripts/build-installers.ps1 -Version 0.9.3 -MakeNsis "C:\Program Files (x86)\NSIS\makensis.exe"

The user installer writes to %LOCALAPPDATA%\Programs\SoundMixer without UAC. The machine installer writes to %ProgramFiles%\SoundMixer through an unelevated bootstrap and a controlled elevated file/registry phase. Both support normal interactive installation, /S, and /SILENTWITHPROGRESS. The user installer also supports the standard NSIS /D= override; the machine installer rejects every directory other than %ProgramFiles%\SoundMixer.

The WinGet manifest uses the machine installer, whose bootstrap requests elevation only for the protected file and registry phase. The user installer remains available as a release asset for direct installation without UAC.

To prepare the five release assets, checksums, and the four WinGet 1.12 manifests locally:

./scripts/prepare-release.ps1 -Version 0.9.3
winget validate --manifest dist/winget

GitHub Actions tests branch and pull-request builds, but publishes a GitHub Release only for a pre-existing X.Y.Z tag that exactly matches sound_mixer.__version__. Optional Authenticode signing requires all three repository secrets: WINDOWS_SIGNING_CERTIFICATE_BASE64, WINDOWS_SIGNING_CERTIFICATE_PASSWORD, and WINDOWS_TIMESTAMP_URL. With none configured, the same release is produced unsigned and verified by SHA-256. When signing is configured, SoundMixer.exe is signed before packaging, NSIS signs the embedded uninstaller, and the completed installers are signed last.

Running the tests

python -m pytest

Tests run in parallel via pytest-xdist (configured in pytest.ini). Tests that need real Windows APIs (audio devices, the registry) are skipped on non-Windows platforms.

Features

Independent volume and mute controls for the system and every active audio application, with app icons and readable display names.
Persistent per-application levels, mute states, hotkeys, overlay layout, and other preferences in a human-editable JSON file.
Named volume presets with separate application and system volume/mute levels, global toggle shortcuts, and optional single-application isolation.
Event-driven application volume and mute synchronization, including changes made in the Windows mixer. External changes are saved and shared across the application's sessions. Each newly created session receives its saved state, including additional sessions within an already running process.
Compact always-on-top overlay with optional Windows 11 acrylic transparency, accent-colored focus, and automatic recovery from off-screen positions.
Horizontal and vertical layouts with independent saved size and position.
Mouse, scroll wheel, and layout-aware arrow-key controls.
Long application names scroll back and forth on row hover, using the same animation as the controls guide.
Configurable global hotkeys, including overlay and mini-widget toggles, volume adjustment, focus navigation, and mute.
Optional transparent mini widget for quick volume and mute control. Drag its pin within 24 pixels of a screen edge and release to dock. Left/right docking stacks applications from top to bottom with display-only volume sliders; scrolling adjusts volume and clicking toggles mute as before. Top/bottom docking keeps the horizontal view. Drag away from the edge to undock.
The mini widget updates when a displayed application's process exits, using Windows process notifications without background polling. Applications with several audio processes remain listed while another audio process is running.
Settings grouped into Application, Volume, Main widget, and Mini widget categories, with separate hotkey and application-list tabs.
Whitelist and ignored-app filters shared by the overlay and mini widget.
System tray controls, optional launch at Windows login, and a setting to show the overlay immediately on startup.
Adjustable interface scale, volume steps, tooltip delay, and transparency.
Overlay and mini widget scaling is capped at 300% including the system display scale. At 200% system scaling, each widget allows up to 150%. Limits follow each window's display and update when its DPI changes. Saved scale preferences are preserved and automatically limited while displayed on a higher-DPI screen.
Optional background scanning for audio child processes created by selected launchers, sandboxes, and other host applications.

Application audio subscriptions stay active with either widget shown or hidden. Session events are batched in 50 ms windows; changing volume does not require a full session scan. When subscriptions are healthy and optional launcher scanning is off, idle audio synchronization does not periodically scan sessions or processes. If subscriptions fail, session polling runs every 5 seconds with a visible widget or every 30 seconds with both hidden. Subscription retries back off from 5 to 30 seconds, and polling stops after recovery. Changing the default output or restoring the audio service reconnects subscriptions and refreshes application sessions.

Optional launcher scanning checks full executable paths. While no configured launcher is running, its interval doubles up to 30 seconds (or the configured interval when that is already longer). Detection can therefore take up to that interval. Finding a launcher restores the configured interval. Disabling scanning stops its timer and resets the backoff.

Hidden main-widget updates are deferred until it is shown. Volume-only changes reuse the mini widget's layout. Application name and icon caches each retain at most 256 recently used entries, with no cleanup timer. Window-title retries run only while a widget is visible.

Extra details

Settings file (`settings.json`)

Schema version 14 adds presets, active_preset_id (null for normal mode), and isolation_restore (saved application states temporarily overridden by isolation). Each preset has an immutable id, a name, an apps map keyed by normalized executable path with volume/muted values, master_volume, master_muted, an optional isolated_app, and a hotkey with combo/enabled fields. Normal levels remain in app_volumes, master_volume, and master_muted. The default_mode hotkey returns to normal mode. Existing settings migrate automatically.

Using presets

Open Settings > Presets and use the plus button to create a preset. Rename it, drop local .exe files or application shortcuts into its card, and set application and system volume/mute levels. The arrow button opens that preset's shortcut row. Use the card's activation button or the Normal mode button to select a mode. These edits take effect only after OK; Cancel discards the preset draft.

Up to nine presets are supported. The overlay keeps the Sound Mixer title and shows P1–P9 beside the monitoring toggle (or Settings when the toggle is hidden), in both layouts. Numbers follow the preset list order; hover over the indicator to see its name. Click the indicator to choose another profile or normal mode from a popup menu; the active profile is checked and profile names appear on hover. Normal mode has no indicator. Settings files with more than nine presets load only the first nine unique profiles; if the active profile is outside that limit, normal mode is selected. Volume changes arriving while Settings is open are preserved for fields you did not edit, including applications automatically added in the background.

Assign each preset an optional global shortcut under Hotkeys. Press it once to activate the preset and again to return to normal mode. The separate Normal mode shortcut always restores normal levels. Shortcuts pause while Settings is open. Duplicate enabled shortcuts are rejected, and holding a preset shortcut does not toggle it repeatedly. The last active mode is restored when Sound Mixer starts.

While a preset is active, changes from either widget, hotkeys, or the Windows mixer update that preset. An allowed application is automatically added on its first volume or mute change. Applications absent from the preset use their normal levels. Whitelist rules limit ordinary preset control; excluded entries remain saved. The overlay shows the mode name, also available in the mini widget tooltip.

Each application row has an isolation switch. Only one can be selected per preset; selecting another transfers isolation. All other applications are held at 0%, including hidden applications, applications outside the whitelist, and newly created audio sessions. Their saved levels are preserved and their controls are disabled. Removing the isolated application or excluding it from the whitelist clears isolation. A temporarily closed isolated application does not clear it.

An external attempt to change an isolated-out application's volume or mute is reverted and triggers a Windows system notification explaining the active preset and isolated application. Notifications are limited to one every 10 seconds across all applications and presets, without a delayed queue. External changes made by an application itself are handled the same way. Windows notification preferences may hide messages; audio isolation still works. Sound Mixer's own audio writes, initial sessions, and unchanged or obsolete events do not trigger messages.

Switching presets applies the destination preset's levels and normal levels for applications absent from it. Returning to normal mode restores normal application and system levels. Deleting the active preset returns to normal mode. Closing Sound Mixer leaves the current Windows audio levels in place.

Settings location and fields

Source runs keep settings.json next to the source tree. A packaged executable uses %LOCALAPPDATA%\GetItSimple\SoundMixer\settings.json unless it is started with --portable. Portable mode keeps settings next to the executable when that directory passes a real write check and otherwise falls back to LocalAppData. A legacy file beside an executable is migrated atomically only when the target file does not already exist. Migration and runtime warnings are written to the rotating %LOCALAPPDATA%\GetItSimple\SoundMixer\logs\sound-mixer.log file (1 MiB, two backups). The file is plain JSON and is safe to edit by hand while the app is not running. If the format changes in a future version, it is migrated automatically on load.

The application lists accept dropped Windows shortcuts (.lnk) and resolve them to their target executables; duplicate shortcuts to the same application create only one entry. Broken shortcuts and shortcuts to non-executable targets display an error.

Managed-app and whitelist entries must be absolute paths to existing local .exe files. UNC paths, Windows device paths, mapped network drives, directories, missing files, and other extensions are ignored before executable metadata is read.

Uninstall always removes the current user's SoundMixer login Run value, independently of the setting-data purge option. A machine uninstaller can only remove that value for the user who launched it. Selecting the purge option also removes settings and rotating logs for that user.

Field	Type	Description
`version`	integer	Settings schema version, used for migrations.
`master_volume`	float (0.0-1.0)	System master volume level.
`master_muted`	bool	System master mute state.
`app_volumes`	object	Per-application volume/mute, keyed by the lowercase executable path with forward slashes (e.g. `"d:/games/mygame/game.exe"`), so two apps that share a file name keep separate settings. Each value is `{ "volume": float, "muted": bool }`. A bare executable name (e.g. `"chrome.exe"`) is still read as a legacy key and applies to any app with that file name.
`hotkeys`	array	Global hotkey bindings. Each entry is `{ "action": string, "combo": string, "enabled": bool }`.
`presets`	array	Up to nine named profiles containing application and system volume/mute, an optional isolated application, and a shortcut.
`active_preset_id`	string or null	Last active preset ID; null selects normal mode.
`isolation_restore`	object	Normal application states preserved before temporary isolation, including apps without an explicit normal entry.
`autostart_enabled`	bool	Whether the app starts automatically on Windows login.
`overlay`	object	Overlay window state: `"layout_mode"` (`"horizontal"` or `"vertical"`), `"visible_on_start"` (bool), and one `{ "x", "y", "width", "height" }` (pixels) block per layout mode under `"horizontal"` and `"vertical"`, so each mode keeps its own position and size.
`tooltip_delay_ms`	integer	Delay, in milliseconds, before action button tooltips appear.
`volume_step`	object	`{ "arrow": float, "scroll": float }` - volume change per arrow-key press and per scroll wheel notch.
`ui_scale`	float (0.5-3.0)	Overlay interface scale factor (fonts, icons, sliders). 1.0 is 100%.
`default_app_volume`	float (0.0-1.0)	Initial volume applied to apps the first time they appear, if not already in `app_volumes`.
`transparency_enabled`	bool	Whether the overlay background uses the translucent acrylic effect. If disabled, the overlay has a solid background.
`ignored_apps`	array of string	Lowercase executable paths (e.g. `"d:/games/mygame/game.exe"`) hidden from the main entry list. Legacy bare executable names (e.g. `"discord.exe"`) still hide every app with that file name. Ignored entries can be revealed via the expand button.
`language`	string	Windows language code discovered from `sound_mixer/i18n//strings.json`, or `"system"` to follow the Windows locale. Defaults to `"system"`. Changes take effect immediately when saved from Settings. Missing translations fall back to English.
`subprocess_management`	object	`{ "interval_seconds": int, "apps": [{ "path": string, "enabled": bool }] }` - shared polling interval and the list of host executables (e.g. sandbox/launcher apps) whose child processes need active background scanning because they don't trigger the normal session-created event. The scan itself is also gated by a session-only on/off switch in the overlay (not persisted - always starts off).
`whitelist`	object	`{ "enabled": bool, "apps": [{ "path": string, "enabled": bool }] }` - optional display filter for both the main overlay and mini widget. Hold the left mouse button on a row's drag handle in Settings and drag vertically within the list to reorder it; enabled apps follow that order in both widgets, with unlisted apps afterward when filtering is off. Full normalized paths distinguish same-named apps; bare session names fall back to matching an enabled path's file name.
`mini_widget`	object	`{ "enabled": bool, "x": int, "y": int, "dock_edge": string, "scale": float, "background_transparency": float, "show_master": bool, "show_above_taskbar": bool }` - mini widget visibility, position, independent 0.5-3.0 scale, app tile background transparency (0 = opaque, 1 = transparent; default 0.8), optional master volume in first position (default false), and display above the taskbar (default false). Enabling display above the taskbar allows placement across the full screen, including the taskbar area, and maintains window stacking without taking keyboard focus. Disabling it moves the widget back into the work area. `dock_edge` is `""` (free, the default), `"left"`, `"right"`, `"top"`, or `"bottom"`; docking survives restarts, scale changes, and session updates. Side docking uses a vertical app list with non-interactive volume indicators, wrapping into additional columns when needed. Settings schema 12 adds docking without changing existing positions or preferences.

Hotkey actions

Settings schema 13 adds unassigned mini widget navigation, volume, and system volume visibility shortcuts. Migration preserves existing shortcut assignments.

Action	Default combo	Effect
`toggle_overlay`	`ctrl+alt+num5`	Show/hide the overlay.
`default_mode`	(none)	Return to normal mode and restore its volume/mute levels.
`preset:`	(none)	Toggle the identified preset; generated from its `hotkey` field in `presets`.
`toggle_mini_widget`	(none)	Show/hide the mini volume widget and persist the state.
`mini_focus_next`	(none)	Select the next mini widget entry, wrapping to the first.
`mini_focus_prev`	(none)	Select the previous mini widget entry, wrapping to the last.
`mini_volume_up`	(none)	Increase the selected mini widget entry's volume by the arrow step.
`mini_volume_down`	(none)	Decrease the selected mini widget entry's volume by the arrow step.
`toggle_mini_master`	(none)	Show/hide system volume in the mini widget and persist the state.
`volume_up`	(none)	Increase the focused entry's volume by the arrow step.
`volume_down`	(none)	Decrease the focused entry's volume by the arrow step.
`focus_next`	(none)	Move focus to the next entry.
`focus_prev`	(none)	Move focus to the previous entry.
`mute_toggle`	(none)	Toggle mute on the focused entry.

Hotkey combos are stored as +-separated key names, e.g. ctrl+alt+num5, ctrl+shift+f9, win+s. In Settings they are shown key names such as Ctrl (Left), Alt (Left), and NumPad 5 as selectors inside the same shortcut input. Modifier keys: ctrl, alt, shift, win. Numpad digit keys are written as num0-num9.

The mini widget keeps its own selected entry, marked with an accent-colored border. Clicking or scrolling an entry selects it without changing the main widget's selection. Navigation follows the displayed application order and includes system volume only when its display is enabled. Initially, or when the selected entry disappears, the first available entry is selected. Selection survives hiding and showing the mini widget but resets on application restart. Mini widget navigation and volume shortcuts only act while the widget is shown; both visibility toggles also work while it is hidden. All mini widget shortcuts are unassigned and disabled by default. Configure them in Settings > Hotkeys.

Known limitations

True exclusive-fullscreen games (not borderless or "fullscreen windowed") can render above the overlay; use borderless/windowed fullscreen mode for the overlay to remain visible.
The acrylic blur effect requires Windows 11 22H2 or later; on older Windows versions the overlay falls back to a plain semi-transparent background.
On startup, the overlay briefly flashes near its last position and then hides again. This is required for the acrylic blur to render correctly once the overlay is later shown via a hotkey or the tray. With "Start opened" enabled the same flash still happens, and the overlay is reopened right after it.
Global hotkeys are subject to Windows UIPI: an elevated foreground application will not receive hotkeys from a non-elevated Sound Mixer, and vice versa.
Newly started applications appear through audio-session notifications. When notifications are unavailable, detection follows the fallback polling interval described above. Optional launcher scanning uses its separate adaptive interval.
An application with multiple audio sessions is shown as a single entry; volume and mute changes apply to all of its sessions.
"System Sounds" has no dedicated entry; use the master volume entry to control it.
The overlay position is stored in raw pixel coordinates. If a monitor is disconnected or resolution changes, the overlay may appear off-screen and need to be dragged back manually.
If SoundMixer.exe is moved after enabling autostart, the registry entry still points at the old path; re-enable autostart from Settings to update it.

Supported languages

The application includes 24 languages:

Language	Windows language code
Bulgarian	`bg`
Chinese (Simplified, mainland China)	`zh-CN`
Croatian	`hr`
Czech	`cs`
Danish	`da`
Dutch	`nl`
English	`en`
Finnish	`fi`
French	`fr`
German	`de`
Greek	`el`
Hungarian	`hu`
Italian	`it`
Japanese	`ja`
Korean	`ko`
Norwegian Bokmål	`nb`
Polish	`pl`
Portuguese (Portugal)	`pt-PT`
Romanian	`ro`
Slovak	`sk`
Spanish (wording for Spain)	`es`
Swedish	`sv`
Turkish	`tr`
Ukrainian	`uk`

Languages are discovered automatically from sound_mixer/i18n//strings.json and included in each build. English (en) is the base language; missing translated keys use the English text. Display names come from Windows. System language detection prefers an exact locale match, then its parent language, then English.

How to add a new translation

Add one file. Copy sound_mixer/i18n/en/strings.json to sound_mixer/i18n//strings.json. Use a Windows locale code for the directory name, such as de or pt-BR.
Translate the values. Keep the JSON keys unchanged and save the file as UTF-8. A partial translation is supported: omitted keys use English automatically.
Build. Run python build.py. The new language appears in Settings automatically; no language registry, loader branch, or language-specific tests are needed. Version bumps follow the normal project release rules.

The Missing your language? button below the language selector opens a short guide. To share a translation, submit its JSON file to this project on GitHub.

When adding, changing, or removing UI strings, update the English catalog and every existing language catalog, including languages contributed later. Translation-content and UI tests use English; generic tests cover language discovery and fallback.

Third-party packages

Package	License	Notes
pycaw	MIT
comtypes	MIT
PySide6	LGPL-3.0
psutil	BSD-3-Clause
PyInstaller	GPL-2.0 with Bootloader Exception	build tool only
pytest	MIT	test only
pytest-xdist	MIT	test only

Windows Sound Mixer

Sound Mixer overlay demo

Run, Build, Test details

Install via WinGet

Sound Mixer is available on WinGet as GetItSimple.SoundMixer:

winget install --id GetItSimple.SoundMixer --exact --source winget

Running from source

pip install -r requirements.txt
python -m sound_mixer

Building a standalone executable

python build.py

Building the NSIS installers

NSIS 3.12 is required. Build the application first, then compile both x64 installer scopes with warnings treated as errors:

python build.py
./scripts/build-installers.ps1 -Version 0.9.3 -MakeNsis "C:\Program Files (x86)\NSIS\makensis.exe"

To prepare the five release assets, checksums, and the four WinGet 1.12 manifests locally:

./scripts/prepare-release.ps1 -Version 0.9.3
winget validate --manifest dist/winget

Running the tests

python -m pytest

Tests run in parallel via pytest-xdist (configured in pytest.ini). Tests that need real Windows APIs (audio devices, the registry) are skipped on non-Windows platforms.

Features

Independent volume and mute controls for the system and every active audio application, with app icons and readable display names.
Persistent per-application levels, mute states, hotkeys, overlay layout, and other preferences in a human-editable JSON file.
Named volume presets with separate application and system volume/mute levels, global toggle shortcuts, and optional single-application isolation.
Event-driven application volume and mute synchronization, including changes made in the Windows mixer. External changes are saved and shared across the application's sessions. Each newly created session receives its saved state, including additional sessions within an already running process.
Compact always-on-top overlay with optional Windows 11 acrylic transparency, accent-colored focus, and automatic recovery from off-screen positions.
Horizontal and vertical layouts with independent saved size and position.
Mouse, scroll wheel, and layout-aware arrow-key controls.
Long application names scroll back and forth on row hover, using the same animation as the controls guide.
Configurable global hotkeys, including overlay and mini-widget toggles, volume adjustment, focus navigation, and mute.
Optional transparent mini widget for quick volume and mute control. Drag its pin within 24 pixels of a screen edge and release to dock. Left/right docking stacks applications from top to bottom with display-only volume sliders; scrolling adjusts volume and clicking toggles mute as before. Top/bottom docking keeps the horizontal view. Drag away from the edge to undock.
The mini widget updates when a displayed application's process exits, using Windows process notifications without background polling. Applications with several audio processes remain listed while another audio process is running.
Settings grouped into Application, Volume, Main widget, and Mini widget categories, with separate hotkey and application-list tabs.
Whitelist and ignored-app filters shared by the overlay and mini widget.
System tray controls, optional launch at Windows login, and a setting to show the overlay immediately on startup.
Adjustable interface scale, volume steps, tooltip delay, and transparency.
Overlay and mini widget scaling is capped at 300% including the system display scale. At 200% system scaling, each widget allows up to 150%. Limits follow each window's display and update when its DPI changes. Saved scale preferences are preserved and automatically limited while displayed on a higher-DPI screen.
Optional background scanning for audio child processes created by selected launchers, sandboxes, and other host applications.

Extra details

Settings file (`settings.json`)

Using presets

Settings location and fields

Field	Type	Description
`version`	integer	Settings schema version, used for migrations.
`master_volume`	float (0.0-1.0)	System master volume level.
`master_muted`	bool	System master mute state.
`app_volumes`	object	Per-application volume/mute, keyed by the lowercase executable path with forward slashes (e.g. `"d:/games/mygame/game.exe"`), so two apps that share a file name keep separate settings. Each value is `{ "volume": float, "muted": bool }`. A bare executable name (e.g. `"chrome.exe"`) is still read as a legacy key and applies to any app with that file name.
`hotkeys`	array	Global hotkey bindings. Each entry is `{ "action": string, "combo": string, "enabled": bool }`.
`presets`	array	Up to nine named profiles containing application and system volume/mute, an optional isolated application, and a shortcut.
`active_preset_id`	string or null	Last active preset ID; null selects normal mode.
`isolation_restore`	object	Normal application states preserved before temporary isolation, including apps without an explicit normal entry.
`autostart_enabled`	bool	Whether the app starts automatically on Windows login.
`overlay`	object	Overlay window state: `"layout_mode"` (`"horizontal"` or `"vertical"`), `"visible_on_start"` (bool), and one `{ "x", "y", "width", "height" }` (pixels) block per layout mode under `"horizontal"` and `"vertical"`, so each mode keeps its own position and size.
`tooltip_delay_ms`	integer	Delay, in milliseconds, before action button tooltips appear.
`volume_step`	object	`{ "arrow": float, "scroll": float }` - volume change per arrow-key press and per scroll wheel notch.
`ui_scale`	float (0.5-3.0)	Overlay interface scale factor (fonts, icons, sliders). 1.0 is 100%.
`default_app_volume`	float (0.0-1.0)	Initial volume applied to apps the first time they appear, if not already in `app_volumes`.
`transparency_enabled`	bool	Whether the overlay background uses the translucent acrylic effect. If disabled, the overlay has a solid background.
`ignored_apps`	array of string	Lowercase executable paths (e.g. `"d:/games/mygame/game.exe"`) hidden from the main entry list. Legacy bare executable names (e.g. `"discord.exe"`) still hide every app with that file name. Ignored entries can be revealed via the expand button.
`language`	string	Windows language code discovered from `sound_mixer/i18n//strings.json`, or `"system"` to follow the Windows locale. Defaults to `"system"`. Changes take effect immediately when saved from Settings. Missing translations fall back to English.
`subprocess_management`	object	`{ "interval_seconds": int, "apps": [{ "path": string, "enabled": bool }] }` - shared polling interval and the list of host executables (e.g. sandbox/launcher apps) whose child processes need active background scanning because they don't trigger the normal session-created event. The scan itself is also gated by a session-only on/off switch in the overlay (not persisted - always starts off).
`whitelist`	object	`{ "enabled": bool, "apps": [{ "path": string, "enabled": bool }] }` - optional display filter for both the main overlay and mini widget. Hold the left mouse button on a row's drag handle in Settings and drag vertically within the list to reorder it; enabled apps follow that order in both widgets, with unlisted apps afterward when filtering is off. Full normalized paths distinguish same-named apps; bare session names fall back to matching an enabled path's file name.
`mini_widget`	object	`{ "enabled": bool, "x": int, "y": int, "dock_edge": string, "scale": float, "background_transparency": float, "show_master": bool, "show_above_taskbar": bool }` - mini widget visibility, position, independent 0.5-3.0 scale, app tile background transparency (0 = opaque, 1 = transparent; default 0.8), optional master volume in first position (default false), and display above the taskbar (default false). Enabling display above the taskbar allows placement across the full screen, including the taskbar area, and maintains window stacking without taking keyboard focus. Disabling it moves the widget back into the work area. `dock_edge` is `""` (free, the default), `"left"`, `"right"`, `"top"`, or `"bottom"`; docking survives restarts, scale changes, and session updates. Side docking uses a vertical app list with non-interactive volume indicators, wrapping into additional columns when needed. Settings schema 12 adds docking without changing existing positions or preferences.

Hotkey actions

Settings schema 13 adds unassigned mini widget navigation, volume, and system volume visibility shortcuts. Migration preserves existing shortcut assignments.

Action	Default combo	Effect
`toggle_overlay`	`ctrl+alt+num5`	Show/hide the overlay.
`default_mode`	(none)	Return to normal mode and restore its volume/mute levels.
`preset:`	(none)	Toggle the identified preset; generated from its `hotkey` field in `presets`.
`toggle_mini_widget`	(none)	Show/hide the mini volume widget and persist the state.
`mini_focus_next`	(none)	Select the next mini widget entry, wrapping to the first.
`mini_focus_prev`	(none)	Select the previous mini widget entry, wrapping to the last.
`mini_volume_up`	(none)	Increase the selected mini widget entry's volume by the arrow step.
`mini_volume_down`	(none)	Decrease the selected mini widget entry's volume by the arrow step.
`toggle_mini_master`	(none)	Show/hide system volume in the mini widget and persist the state.
`volume_up`	(none)	Increase the focused entry's volume by the arrow step.
`volume_down`	(none)	Decrease the focused entry's volume by the arrow step.
`focus_next`	(none)	Move focus to the next entry.
`focus_prev`	(none)	Move focus to the previous entry.
`mute_toggle`	(none)	Toggle mute on the focused entry.

Known limitations

True exclusive-fullscreen games (not borderless or "fullscreen windowed") can render above the overlay; use borderless/windowed fullscreen mode for the overlay to remain visible.
The acrylic blur effect requires Windows 11 22H2 or later; on older Windows versions the overlay falls back to a plain semi-transparent background.
On startup, the overlay briefly flashes near its last position and then hides again. This is required for the acrylic blur to render correctly once the overlay is later shown via a hotkey or the tray. With "Start opened" enabled the same flash still happens, and the overlay is reopened right after it.
Global hotkeys are subject to Windows UIPI: an elevated foreground application will not receive hotkeys from a non-elevated Sound Mixer, and vice versa.
Newly started applications appear through audio-session notifications. When notifications are unavailable, detection follows the fallback polling interval described above. Optional launcher scanning uses its separate adaptive interval.
An application with multiple audio sessions is shown as a single entry; volume and mute changes apply to all of its sessions.
"System Sounds" has no dedicated entry; use the master volume entry to control it.
The overlay position is stored in raw pixel coordinates. If a monitor is disconnected or resolution changes, the overlay may appear off-screen and need to be dragged back manually.
If SoundMixer.exe is moved after enabling autostart, the registry entry still points at the old path; re-enable autostart from Settings to update it.

Supported languages

The application includes 24 languages:

Language	Windows language code
Bulgarian	`bg`
Chinese (Simplified, mainland China)	`zh-CN`
Croatian	`hr`
Czech	`cs`
Danish	`da`
Dutch	`nl`
English	`en`
Finnish	`fi`
French	`fr`
German	`de`
Greek	`el`
Hungarian	`hu`
Italian	`it`
Japanese	`ja`
Korean	`ko`
Norwegian Bokmål	`nb`
Polish	`pl`
Portuguese (Portugal)	`pt-PT`
Romanian	`ro`
Slovak	`sk`
Spanish (wording for Spain)	`es`
Swedish	`sv`
Turkish	`tr`
Ukrainian	`uk`

How to add a new translation

Add one file. Copy sound_mixer/i18n/en/strings.json to sound_mixer/i18n//strings.json. Use a Windows locale code for the directory name, such as de or pt-BR.
Translate the values. Keep the JSON keys unchanged and save the file as UTF-8. A partial translation is supported: omitted keys use English automatically.
Build. Run python build.py. The new language appears in Settings automatically; no language registry, loader branch, or language-specific tests are needed. Version bumps follow the normal project release rules.

The Missing your language? button below the language selector opens a short guide. To share a translation, submit its JSON file to this project on GitHub.

Third-party packages

Package	License	Notes
pycaw	MIT
comtypes	MIT
PySide6	LGPL-3.0
psutil	BSD-3-Clause
PyInstaller	GPL-2.0 with Bootloader Exception	build tool only
pytest	MIT	test only
pytest-xdist	MIT	test only

Sound Mixer Get it Simple

README

Windows Sound Mixer

Install via WinGet

Running from source

Building a standalone executable

Building the NSIS installers

Running the tests

Settings file (`settings.json`)

Using presets

Settings location and fields

Hotkey actions

Known limitations

Supported languages

Sound Mixer Get it Simple

README

Windows Sound Mixer

Install via WinGet

Running from source

Building a standalone executable

Building the NSIS installers

Running the tests

Settings file (`settings.json`)

Using presets

Settings location and fields

Hotkey actions

Known limitations

Supported languages

Sound Mixer Get it Simple

README

Windows Sound Mixer

Install via WinGet

Running from source

Building a standalone executable

Building the NSIS installers

Running the tests

Settings file (settings.json)

Using presets

Settings location and fields

Hotkey actions

Known limitations

Supported languages

Sound Mixer Get it Simple

README

Windows Sound Mixer

Install via WinGet

Running from source

Building a standalone executable

Building the NSIS installers

Running the tests

Settings file (settings.json)

Using presets

Settings location and fields

Hotkey actions

Known limitations

Supported languages

Settings file (`settings.json`)

Settings file (`settings.json`)