🎶 MUSOF Player

V12.5.0 Build from files, URLs, or podcast feeds; play offline via .musof
A new version is ready
Show:

Recent libraries

Drop .musof or audio files here

MP3, M4A, FLAC, OGG/Opus · RSS/XML podcast feeds · raw formats (WAV/PCM) are rejected

Add from web

Saving not available. This browser doesn't support the File System Access API (showSaveFilePicker / showDirectoryPicker), which V3 requires for packaging and downloads. You can still play .musof files; building is disabled. Try Chrome, Edge, Opera, or Safari 18+.
Working…
0%

Package 0 file(s)

Bulk fill (applies to tracks missing the field)

No image chosen

Edit library 0 file(s)

Reorder, edit metadata, or remove tracks.
Library ●
Play queue
—
Note 0:00.0
0:00
0:00
Skip regions
Lyrics / Transcript / Notes

Open a library and pick a track to start playing.

Theme

#5A57D4
18px
#5A57D4
From palette
135°
X 30%
Y 25%

Audio-reactive gradients. High power use — lower the frame rate or gradient count to save battery.

–––
Baseline offset
0%
Gradient count
5
Max frame rate
30 fps

Settings

MUSOF / MUST Formats MUSOF (MUltiple SOng Files, pronounced "MUS-OF") — custom binary container. v3: bytes 0–4 magic MUSOF; byte 5 version; bytes 8–11 index size (uint32 BE); UTF-8 JSON index (n,tt,ar,al,yr,gn,mt,to,tz,tm,co,cz,cm,ao,az,so,sz,xo,xz,vo,vz,ul); then data [thumbs][covers][audio][srt][txt][vtt]. Skip regions stored as [SKIP] cues in SRT. VTT slot holds WebVTT with word-level timestamps.
MUST (MUltiple Song TAR) — standard POSIX ustar TAR archive. First entry index.jsonl (JSONL). Per-track: {NNN}/a.{ext} audio, {NNN}/t.{ext} thumb, {NNN}/c.{ext} cover, {NNN}/s.srt lyrics/transcript (skip regions as [SKIP] cues), {NNN}/x.txt description, {NNN}/v.vtt WebVTT lyrics, {NNN}/u.url source URL. Extractable with tar.

Privacy Note
External JS Libraries: Font Awesome 6 Free (kit.fontawesome.com)
External JS Frameworks: None
External Web Fonts: None (system fonts only)
External APIs: ListenBrainz (api.listenbrainz.org) — used only when you enable scrobbling and supply your own user token; otherwise none. URLs and RSS feeds you paste are fetched directly by your browser from the servers you specify; this page has no backend. Uses only browser APIs: File, Blob, FileReader, URL, Audio, Canvas, TextEncoder, TextDecoder, DataView, DOMParser, fetch, MediaSession, MediaMetadata, matchMedia, IndexedDB, Cache, ServiceWorker, LaunchQueue, ShareTarget, showOpenFilePicker, showSaveFilePicker, showDirectoryPicker, FileSystemWritableFileStream, WakeLock, DocumentPictureInPicture, Fullscreen, Gamepad, AudioContext, AnalyserNode, atob
All processing runs locally in your browser; nothing is uploaded.

Version

ListenBrainz scrobbling

Not signed in

Paste your ListenBrainz user token to enable scrobbling. The token is stored only in this browser (IndexedDB) and sent only to ListenBrainz.

Queued listens0

Controls

Playback
APlay / pause
XShuffle
YRepeat mode
LB / RBPrevious / next track
LT / RT · D-pad ◄► · stick XSeek −10s / +10s
D-pad ▲▼ · L-stick YVolume up / down
R-stick YPrevious / next track
Sync editor
APlay / pause
XStamp timestamp
Y / BShift all ±0.1s
LB / RBPrevious / next line
LT / RTPrevious / next word
D-pad ◄►Seek −10s / +10s
D-pad ▲▼Seek −5s / +5s
StartSave sync

Standard controllers work as-is. If a stick feels swapped or inverted, calibrate it here.

Connect a controller to calibrate.

Playback
SpacePlay / pause
◄ / ►Seek −10s / +10s
▲ / ▼Volume up / down
J / LSeek −5s / +5s
P / NPrevious / next track
SShuffle
RRepeat mode
Sync editor
K / EnterStamp timestamp
I / SpacePlay / pause
J / LSeek −5s / +5s
▲ / ▼Previous / next line
◄ / ►Previous / next word