Studio Mixer
A full-featured browser-based multi-track audio & video editor. Arrange, mix, crossfade, add video, and export — all offline, all free.
Key Features
Unlimited Tracks
Add as many audio tracks as you need. Each track has Solo, Mute and an individual volume fader in the built-in mixer.
Magnetic Snap System
Clips snap to each other's edges and the playhead for precise alignment. Hold Ctrl to move freely without snapping.
Fades & Crossfades
Drag fade handles for manual fade-in/out. Overlapping clips automatically crossfade with equal-power curves.
Video Preview & Scoring
Drop a video file to sync it with the timeline. Import audio from video, score to picture, and export audio+video together as MP4, WebM or MOV.
Volume Mixer & Knob
Per-track vertical faders (0–200%) in a collapsible mixer panel. Per-clip volume with a rotary knob in the inspector. Double-click to reset.
Clip Duplication
Alt+Drag any clip to instantly create a copy. Combined with split and trim, you can rearrange audio at lightning speed.
Undo & Redo
Full snapshot-based history. Ctrl+Z to undo, Ctrl+Y to redo — every action is reversible.
Save & Load Projects
Save your entire session — audio files, clips, mixer settings — as a single compressed .smx file. Reopen it anytime with Ctrl+O to continue where you left off. Video is not included to keep file sizes manageable — simply re-import it after loading.
Media Pool & Drag-Drop
Import audio files into a media pool, then drag them onto any track. Reuse clips as often as you like.
Export Audio & Video
Export as MP3, WAV, OGG, FLAC — or as MP4, WebM, MOV when a video is loaded. Solo/Mute states are respected during export.
ENDE Music Integration
Load royalty-free music directly from ENDE's library into the Studio Mixer — perfect as a background track for your project.
Resizable Layout
Drag handles to resize panels. Collapsible sections for Video Preview, Audio Pool and Mixer. Track height adjustable from 60–400px.
Fully Private
Everything runs in your browser using the Web Audio API and FFmpeg WASM — your files never leave your device.
How To Use
Import Audio
Click Add Media or drag & drop audio files (MP3, WAV, OGG, FLAC, etc.) into the Audio Pool on the left. Each file is decoded and shows its waveform. You can import as many files as you need.
Arrange on the Timeline
Drag clips from the Audio Pool onto any track in the timeline. Move them horizontally to position them in time, or drag between tracks to rearrange layers. Clips snap magnetically to each other's edges and the playhead — hold Ctrl to move freely without snapping.
Edit Clips
Fine-tune your arrangement with these tools:
- Trim: Drag the left or right edge of a clip to adjust its start or end point.
- Split: Select a clip, position the playhead, and press B to split it in two.
- Duplicate: Hold Alt and drag a clip to create a copy instantly.
- Fade: Drag the small triangles at the top corners of a clip to add fade-in or fade-out. Overlapping clips crossfade automatically.
- Delete: Select a clip and press Delete or Backspace.
Mix & Balance
Use the Mixer panel at the bottom-left with vertical faders for each track (0–200%). Double-click a fader to reset it to 100%. Adjust individual clip volume with the rotary knob in the Inspector (right panel) — double-click the knob to reset. Use S (Solo) and M (Mute) buttons on each track to isolate or silence tracks. Soloed tracks highlight yellow, muted tracks highlight red.
Save & Load Projects
Press Ctrl+S or use File → Save Project to download your entire session as a compressed .smx file. All audio files, clip positions, mixer volumes, solo/mute states and zoom settings are included. Video is not saved in the project file to keep the download size manageable — simply re-import it after loading. To continue later, press Ctrl+O or use File → Open Project to reload it — everything is restored exactly as you left it.
Add Video (Optional)
Drop a video file into the Video Preview area at the top-right. The video syncs with the timeline — play, pause and seek work in lockstep. Check Import Audio to extract the video's audio onto a track. If the video is longer than your audio, the timeline extends automatically.
Export
Choose your format — MP3, WAV, OGG, FLAC for audio, or MP4, WebM, MOV when a video is loaded — and click Download. The export renders offline at full quality via FFmpeg WASM. Solo/Mute states are respected: muted tracks are excluded, and if any track is soloed, only soloed tracks are included.
Keyboard Shortcuts
Perfect For
Frequently Asked Questions
There is no limit — add as many tracks as you need. The app starts with 3 tracks by default. Each track has its own Solo, Mute and volume fader in the mixer.
Yes! Drop a video file into the Video Preview area. It syncs with the timeline so you can score to picture. You can also import the video's audio track. When exporting, choose a video format (MP4, WebM, MOV) to combine your mix with the video.
Audio: MP3, WAV, OGG, FLAC. Video (when a video is loaded): MP4, WebM, MOV. The offline render is powered by FFmpeg WASM — everything happens locally in your browser.
Yes. Muted tracks are excluded from the export. If any track is soloed, only soloed tracks are included — just like in a professional DAW.
Yes! Space for play/pause, B to split, Delete to remove clips, Ctrl+Z / Ctrl+Y for undo/redo, Ctrl+S / Ctrl+O for save/open project, scroll wheel to zoom, Alt+Drag to duplicate clips, and more. Press ? inside the app to see the full list.
Yes! Press Ctrl+S or use File → Save Project to download a compressed .smx file containing all your audio files, clip positions, mixer settings and zoom state. Video is not included to keep the file size manageable — just re-import it after loading. To continue later, press Ctrl+O or use File → Open Project. The file uses gzip compression to keep the download as small as possible.
Yes! When opened from a song page, the music track is automatically pre-loaded into the Studio Mixer so you can start editing right away.
No. Everything — playback, mixing, rendering and export — runs entirely in your browser using the Web Audio API and FFmpeg WASM. Your files never leave your device.
Ready to mix?
Launch the Studio Mixer directly in your browser — no installation, no sign-up.
Start Studio Mixer
