Free Open-Source AI Stem Separator
That Runs Entirely on Your Computer
StemDeck is a free and open-source stem separation application that can split songs into up to six individual stems: vocals, drums, bass, guitar, piano and other.
Unlike popular cloud-based services such as Moises or LALAL.AI, StemDeck processes everything locally on your own computer. There are no subscriptions, processing credits, accounts or audio uploads to external servers.
Drop in an audio file, let StemDeck separate it using the open-source Demucs htdemucs_6s neural network, and the results appear inside a DAW-style multitrack environment where you can solo stems, adjust levels, loop sections, inspect waveforms and export individual parts or a custom mix.
For musicians who want AI-powered stem separation without another subscription or cloud service, StemDeck is a particularly interesting free alternative.
Six-Stem AI Separation
StemDeck can separate a complete recording into six components:
- Vocals
- Drums
- Bass
- Guitar
- Piano
- Other
Under the hood, it uses Demucs htdemucs_6s, Meta AI’s open-source six-stem neural separation model.
This is important because StemDeck isn’t simply applying EQ or center-channel cancellation. It uses machine-learning-based source separation to estimate the individual musical components contained within a finished mix.
Process Everything Locally
Perhaps StemDeck’s biggest advantage is that your audio does not need to leave your computer.
There is:
- No cloud processing
- No account
- No login
- No subscription
- No processing quota
The developers explicitly state that audio remains on the user’s machine.
This has obvious privacy advantages, but it also means you aren’t dependent on a remote service remaining available.
Once the necessary models have been downloaded, local files can be processed offline.
Import Your Own Audio Files
StemDeck accepts a useful range of common audio and media formats:
- MP3
- WAV
- FLAC
- OGG / Opus
- M4A
- MP4
Simply drag a compatible file onto the import area and begin processing.
YouTube URL Support
StemDeck can also accept a YouTube URL as an input source.
The project stresses that StemDeck is fundamentally a stem-separation tool, not a downloader, and YouTube support is intended as a convenience for content that users have the right to process. Downloaded material isn’t stored or redistributed by the StemDeck service because the processing itself happens locally.
Extract Only the Stems You Need
You don’t always need all six stems.
StemDeck allows you to select a subset before processing.
For example, you could request only:
- Vocals
- Drums
or perhaps:
- Bass
- Guitar
- Piano
This is useful when your goal is simply to isolate one instrument for practice, transcription, remixing or analysis.
Automatic “Original” Backing Track
There’s also a clever complement feature.
When you extract only selected stems, StemDeck can create an additional Original lane containing the full recording minus those selected elements.
Extract the vocals, for example, and the complementary track effectively becomes the remaining backing material.
This makes StemDeck particularly useful for:
- Karaoke
- Instrument practice
- Remixing
- Acapella extraction
- Backing-track creation
- Transcription
DAW-Style Multitrack Interface
StemDeck doesn’t simply create several WAV files and leave you to open them elsewhere.
After processing, the stems appear inside a multitrack editor inspired by conventional DAW workflows.
Each separated element occupies its own waveform lane, with synchronized playback across the entire song.
You can:
- Play and pause
- Stop
- Zoom waveforms
- Fit the complete track to the display
- Move through the song
- Define loop regions
This makes it possible to work with the separated audio without immediately opening a DAW.
Per-Stem Mixer
Every stem gets independent mixer controls.
These include:
- Volume
- Mute
- Solo
- Monitor
Multiple stems can be soloed together, while Monitor provides a quick way of listening exclusively to one selected part.
This can be extremely useful for studying a recording.
Want to hear only the bass line?
Solo Bass.
Want drums and bass together?
Solo both.
Want everything except the vocals?
Mute Vocals.
Live VU Meters
StemDeck includes live level meters for each stem.
The meters use post-gain RMS analysis with peak hold and gradual falloff, providing useful visual feedback while balancing the separated elements.
This further reinforces the impression that StemDeck is a small multitrack audio workstation rather than merely a front end for an AI model.
Loop Sections for Practice
The waveform ruler can be used to define loop regions.
Drag across the section you want to repeat and enable Loop.
This makes StemDeck especially interesting for musicians learning songs.
You could isolate the guitar, bass or piano stem, loop a difficult section and repeatedly listen to the part without the distraction of the full arrangement.
Keyboard shortcuts are also provided for transport, seeking and loop points.
Song Analysis
StemDeck goes beyond source separation by automatically analyzing the imported track.
It can provide information including:
- BPM
- Musical key
- Scale
- Key-detection confidence
- Integrated LUFS
- Sample peak in dBFS
BPM analysis uses librosa’s beat tracker, while key estimation uses Albrecht-Shanahan profiles. Loudness is measured according to ITU-R BS.1770.
These tools make StemDeck useful not only for stem extraction but also for studying and preparing material for remixing.
Export a Custom Mix
After adjusting the stems, StemDeck can generate a single mix.wav containing your selected elements summed together.
For example, you could export:
- Drums + bass
- Instrumental backing
- Vocals only
- Rhythm section
- Any custom stem combination
The mixing process uses FFmpeg’s audio mixing capabilities.
Organize Songs in a Library
StemDeck includes a library panel for organizing processed tracks.
Features include:
- Folders
- Search
- Drag-and-drop organization
- Trash
- Relocatable StemDeck data storage
This is useful if you regularly separate songs for practice or analysis rather than treating the application as a one-off conversion utility.
Hardware Acceleration
AI source separation can be computationally demanding, so StemDeck automatically attempts to use the best available processing device.
It supports:
- NVIDIA CUDA on compatible Windows/Linux systems
- Apple MPS acceleration on Apple Silicon
- CPU fallback when GPU acceleration isn’t available
Processing speed therefore depends considerably on your hardware.
A modern GPU can make separation substantially faster, while CPU-only processing may require more patience.
Apple Silicon Support
Apple Silicon Macs receive native MPS acceleration.
The macOS ARM64 version is intended for:
- M1
- M2
- M3
- M4
- Later Apple Silicon processors
Intel Macs are also supported, but separation runs on the CPU.
Windows CPU and NVIDIA Versions
Two pre-built Windows packages are available.
The standard Windows x64 build is CPU-only and is approximately 700 MB.
A separate Windows x64 NVIDIA package includes CUDA support and is approximately 1.6 GB.
Users with compatible NVIDIA hardware should therefore choose the accelerated build.
First-Launch Downloads
StemDeck is free, but users should be aware that the first launch requires additional downloads.
On macOS, setup downloads approximately:
- 500 MB Python runtime
- FFmpeg
- Around 170 MB for the Demucs model
The required components are then cached, so subsequent launches are considerably faster.
No separate system-wide Python installation is required when using the packaged desktop versions.
StemDeck vs Cloud Stem Separators
StemDeck’s own developers are unusually straightforward about its position compared with commercial alternatives.
| Feature | StemDeck | Typical Commercial Service |
|---|---|---|
| Price | Free forever | Freemium / subscription |
| Processing | Local | Cloud |
| Account | None | Usually required |
| Audio upload | No | Yes |
| Offline local files | Yes | Usually no |
| Stems | Up to 6 | Sometimes up to 10 |
| Mobile app | No | Often yes |
| Batch processing | One job at a time | Often available on paid plans |
| Source code | Open source | Proprietary |
| Separation model | Demucs htdemucs_6s | Usually proprietary |
Most importantly, the StemDeck developers themselves acknowledge that commercial services generally use regularly updated proprietary models and may offer higher separation quality, faster processing and more polished musician-oriented tools.
That’s refreshingly transparent.
StemDeck isn’t claiming to beat every commercial competitor. Its proposition is different:
free + private + local + open source.
Best Uses
StemDeck is particularly useful for:
Music Practice
Remove or isolate an instrument and loop difficult sections.
Remixing
Extract vocals, drums, bass and other elements from an existing recording.
Acapellas
Separate vocals from backing material for legitimate remix and creative work.
Transcription
Solo guitar, piano or bass to hear parts more clearly.
Karaoke and Backing Tracks
Remove or reduce the vocal component and practice against the remaining arrangement.
Sampling
Extract individual musical components before further creative processing.
Production Study
Listen to isolated stems to better understand how professional arrangements are constructed.
Open Source
StemDeck is released under the Apache 2.0 license, and the complete source code is publicly available.
Its technology stack includes:
- Python 3.12
- Demucs
- FastAPI
- FFmpeg
- librosa
- Web Audio API
- Tauri v2
- Rust
- yt-dlp
The project can also be self-hosted and run as a local web server or through Docker.
For ordinary musicians, however, none of this technical setup is necessary: pre-built desktop versions are available through the project’s GitHub Releases page.
Strengths
- Completely free
- Open source
- No account required
- No subscription
- No processing credits
- Audio remains on your computer
- Up to six stems
- Demucs htdemucs_6s separation
- Vocals, drums, bass, guitar and piano separation
- DAW-style multitrack interface
- Individual mute, solo and volume controls
- Waveform zooming and looping
- BPM and key analysis
- Integrated LUFS measurement
- Custom mix export
- YouTube URL support
- Apple Silicon acceleration
- NVIDIA CUDA acceleration
- Windows and macOS desktop builds
- Self-hosting and Docker options
Potential Limitations
- Separation quality may not match the latest proprietary commercial models
- CPU processing can be slow
- Only one processing job at a time
- Maximum of six main stems
- No mobile application
- Less polished than established commercial alternatives
- No advanced musician tools such as pitch shifting, synchronized lyrics or click-track generation
- First launch requires downloading additional components and model data
Final Verdict
StemDeck is one of the most interesting free alternatives to subscription-based AI stem separation services.
Its greatest strength isn’t necessarily that it produces better stems than every commercial competitor — even its developers don’t make that claim.
The attraction is freedom.
Your music stays on your computer. There is no account. There are no monthly credits. There is no subscription. The source code is available, and once the necessary model has been downloaded, local files can be processed without depending on a remote service.
More importantly, StemDeck wraps the Demucs separation engine in a genuinely useful musical interface. Waveform lanes, looping, stem mixing, VU meters, BPM/key detection and custom exports mean you can actually work with the separated material rather than simply generating a folder of files.
For musicians practicing songs, producers studying arrangements, remixers, DJs and anyone who regularly needs to isolate vocals or instruments, StemDeck is an excellent free and privacy-friendly tool to keep installed.
Sources :
github.com: https://github.com/stemdeckapp/stemdeck
bbedroomproducersblog.com: https://bedroomproducersblog.com/2026/08/19/stemdeck-stem-splitter/
