Note: I checked this guide against StemDeck’s repository and v0.11.1 release notes on 20 August 2026. I have not installed or benchmarked the app myself. The download sizes and behaviour described here come from the project’s documentation.
StemDeck splits a song into vocals, drums, bass, guitar, piano and “other”, then opens the tracks in a mixer where you can solo, mute, balance and export them. It runs the htdemucs_6s model on your computer. A desktop local-file job needs no account and sends no audio to a server.
StemDeck is built for practice tracks, rough remixes, transcription and checking an arrangement. It is alpha software. The Mac app is unsigned, first launch downloads several large files, and results vary by recording. Install StemDeck from the GitHub release that matches your processor, verify its hash, then test a short file.
Before you download StemDeck
Pick a short recording that you made or have permission to process. A 30-second WAV or MP3 is enough for the first run. Keep the original file somewhere outside StemDeck’s working folders.
- Disk space: allow room for the app, FFmpeg, a Python runtime on macOS and roughly 170 MB for the Demucs model. Leave extra space for WAV exports.
- Internet: first launch downloads the model and other files. Local-file separation can run on the computer after setup.
- Hardware: the app can select CUDA on a compatible NVIDIA system, MPS on Apple Silicon or CPU mode.
- Time: CPU processing works, but it can take much longer than GPU processing. The project publishes no universal speed figure.
StemDeck is pre-1.0 software. Test it with a copy of a non-critical file before putting it into a real project.
Choose the correct download
macOS
StemDeck-macOS-arm64.dmgis for Apple Silicon Macs (M1 and newer).StemDeck-macOS-x64.dmgis for Intel Macs.
The v0.11.1 Mac build has no code signature. Expect Gatekeeper to stop the first launch. Get the DMG from the official v0.11.1 release, verify its SHA-256 hash, then use the app-specific opening instructions in the troubleshooting section.
On first launch, macOS downloads a platform-specific Python runtime and FFmpeg; the separation model downloads on first use. In v0.11.1 the compressed runtime archives are 165,171,633 bytes for Apple Silicon and 243,064,890 bytes for Intel. Their extracted footprint is larger, and completed downloads are reused on later launches.
Windows
StemDeck-Windows-x64.zipis the CPU download. The v0.11.1 asset is 248,290,040 bytes (about 248.3 MB).StemDeck-Windows-x64.NVIDIA.zipis the NVIDIA download. The v0.11.1 asset is 248,289,250 bytes (about 248.3 MB), but first launch can add several GB of CUDA-enabled PyTorch after a compatible GPU and driver are detected.
If you don’t know whether your NVIDIA setup is compatible, start with the CPU ZIP. Extract the whole archive to a normal user folder before running StemDeck.exe. First launch prepares the Python environment and FFmpeg; the Demucs model downloads when you process the first file.
Linux or a local web server
The project documents a source install for macOS and Debian/Ubuntu. Read run.sh before running it on a work machine.
git clone --branch v0.11.1 --depth 1 https://github.com/stemdeckapp/stemdeck.git stemdeck
cd stemdeck
./run.sh setup
HOST=127.0.0.1 PORT=8000 ./run.sh startThe setup script installs FFmpeg and uv, then syncs the Python environment. Keep the source server bound to 127.0.0.1 unless you deliberately add access controls. StemDeck v0.11.1 has no authentication, and its tagged start script otherwise listens on every network interface. Other Linux distributions need FFmpeg and uv installed first. The repository also has Docker and Unraid instructions.
Verify the downloaded file
A checksum tells you whether your file matches the publisher’s release file. It does not audit the program, but it will catch a damaged or different download.
On Windows PowerShell, change the filename if you downloaded the NVIDIA build:
Get-FileHash .\StemDeck-Windows-x64.zip -Algorithm SHA256On macOS:
shasum -a 256 StemDeck-macOS-arm64.dmgCompare the full result with the SHA-256 entry published beside the release assets. If even one character differs, discard the file and download it again from the official release page.
Install StemDeck and complete the first run
- Open the verified DMG on macOS or the fully extracted folder on Windows.
- Move the Mac app to Applications, or run
StemDeck.exefrom its extracted Windows folder. - Let the setup screen fetch its runtime files and FFmpeg. The Demucs model arrives when the first separation starts. A quiet period during a large download is possible.
- Wait for the app to show that setup has finished. Read any error before trying again; the message usually identifies the failed file or network host.
Version 0.11.1 changed the macOS FFmpeg bootstrap after users reported regional download failures. It added a second source, a roughly 20-second failure timeout, retries, clearer errors and four pinned checksums. The timeout, retries and host-specific errors provide more information when setup fails. The app is still unsigned and alpha.
Split a test recording
- On the import bar, leave all six stem chips selected for the first test.
- Drop in a local MP3, WAV, FLAC, OGG/Opus, MP4 or M4A file, then click Process.
- Watch the stages move through analysis, separation and mixing. The first job may pause while
htdemucs_6sdownloads. - When the mixer opens, solo each lane and listen for vocals or instruments leaking into the wrong track.
- Set the levels you want. Export separate stems, or download a WAV mix of the selected tracks.
StemDeck can extract a subset. Click one stem chip while all six are selected to keep only that part, then add more chips as needed. When you choose a subset, the app can create an Original lane containing the rest of the song. Use that lane to compare the extracted stems with the remaining mix.
What six-stem separation can recover
Do not expect studio multitracks. StemDeck estimates what belongs in each channel. Reverb, distorted guitars, layered vocals and overlapping frequencies can bleed between stems. Piano and guitar are especially dependent on the arrangement.
Try the same short section in a lossless format if you have one. Listen at matched levels; a louder stem can seem cleaner than it is. Test the same 30-second passage before processing the full recording.
YouTube import and recording rights
StemDeck can accept a YouTube URL through yt-dlp. That feature does not give permission to download or reuse the audio. Restrict it to your own uploads, public-domain recordings or material for which you have explicit permission, and follow the platform’s terms. Use a local file first so a network import is not a second variable.
Fix common StemDeck problems
macOS says StemDeck is damaged or cannot be verified
Check that you downloaded the ARM64 or x64 DMG that matches your Mac and that its SHA-256 hash matches. Right-click StemDeck and choose Open. If macOS still blocks it, the release notes give this app-specific command:
xattr -dr com.apple.quarantine /Applications/StemDeck.appRun it only against a verified copy of StemDeck. Do not disable Gatekeeper across the computer.
FFmpeg setup fails
Read the final host and error in the setup window. Version 0.11.1 should time out a dead FFmpeg source, retry, then switch sources. A managed network may block GitHub release files. The project exposes STEMDECK_FFMPEG_URL for a controlled mirror. A custom Windows URL skips the built-in checksum check; on macOS, provide and verify STEMDECK_FFMPEG_SHA256 and STEMDECK_FFPROBE_SHA256 with any custom FFmpeg or ffprobe source. Do not use a mirror you cannot authenticate independently.
The first separation looks frozen
The first job downloads about 170 MB of Demucs weights. Check the network, free disk space and app log before closing it. Later jobs should reuse the cached file.
Processing is slow
Look in the startup log for device=cuda, device=mps or device=cpu. Test with a shorter clip and close memory-heavy programs. On Windows, the NVIDIA ZIP cannot make an incompatible GPU or driver work; use the CPU package if CUDA fails.
The six tracks have bleed
Compare a representative section from a lossless source, then check each lane at the same level. Some bleed is a model limitation. If the same instrument keeps landing in two lanes, StemDeck has no manual spectral editor to repair that split.
A long recording is rejected
The server configuration defaults to STEMDECK_MAX_DURATION_SEC=1200, which is 20 minutes. Process a shorter authorised excerpt first. Raising the value also raises processing time, temporary storage and memory demand.
Privacy, licences and commercial work
Local-file separation is documented to run on the computer. First launch still contacts the network for dependencies and the model; the URL importer also needs a connection. For confidential material, finish setup first, use a local file and follow your workplace’s software review rules.
StemDeck’s application code is Apache-2.0 and Demucs source code is MIT. The Demucs maintainer states that the pretrained model weights are not covered by MIT and are provided only for scientific purposes; the archived repository publishes no separate commercial-use grant for htdemucs_6s. Do not infer commercial-use permission from either code licence. Separately, confirm your rights to the source recording and any resulting audio before reuse or distribution.
StemDeck questions
Does StemDeck cost anything?
The project offers the app free of charge and publishes its code under Apache-2.0. The Demucs maintainer’s scientific-purpose restriction for the pretrained weights still applies, along with the rights attached to the recording.
Does StemDeck upload music?
The local-file workflow is documented to process audio on the computer. Setup downloads files, and the optional YouTube importer goes online.
Can it run without a GPU?
Yes. Windows has a CPU package, and the source build can fall back to CPU. Processing time then depends heavily on the processor and the recording length.
Which model does it run?
StemDeck runs htdemucs_6s from Demucs. Its target lanes are vocals, drums, bass, guitar, piano and other.
Should I choose StemDeck or a cloud service?
StemDeck keeps the local-file workflow on your computer and asks for no account. Its documentation does not benchmark cloud services. If you are considering one, compare the same authorised clip, the exported audio, processing time and privacy terms.
How do I uninstall StemDeck?
Remove the app or extracted folder through the operating system. Check the repository’s current data-folder list before deleting caches, because those folders may also contain jobs and exports you want to keep.
Related local audio guides
The MusicGen guide covers local music generation. For speech, the NeMo Speech.cpp setup covers transcription on your own computer.
For the first StemDeck run, choose a 30-second file you are allowed to process, leave all six chips selected and keep the original recording untouched.