Stemdeck

Free, local stem separation. No account. No upload. No subscription.

Drop in an MP3, WAV, FLAC, OGG/Opus, MP4, or M4A file, or paste a YouTube URL, and StemDeck splits the audio into up to six stems (vocals, drums, bass, guitar, piano, other). Play them back in a DAW-style multitrack mixer: mute, solo, balance levels, zoom the waveform, loop a region, and export individual stems or a custom mix. Everything runs locally on your own machine.

Features:

• 6-stem separation via Demucs htdemucs_6s, with auto-detection of the best Torch device (CUDA on NVIDIA, MPS on Apple Silicon, CPU fallback).
• YouTube and local file import. Paste a YouTube URL or drop an MP3, WAV, FLAC, OGG/Opus, MP4, or M4A directly onto the import bar.
• DAW-style waveform editor with min/max sample rendering across all stems, shared normalization, zoom in/out/Fit, loop drag on the ruler, gold playhead overlay, and stem-aligned lanes.
• Stem subset extraction. Click stem chips to choose which stems to keep. Clicking from "all selected" snaps to "only this one"; subsequent clicks add or remove.
• "Original" backing track. When you pick a subset, a 7th lane contains the complement (full song minus selected stems), perfect for A/B reference without doubling.
• Downloadable selected mix. A single mix.wav of just your selected stems, summed via ffmpeg amix.
• Per-stem mixer with volume fader, mute, solo, and "monitor" (solo-only) per stem. State syncs between the preview mixer and the stems sidebar.
• Live VU meters per stem. Post-gain RMS via Web Audio analysers with peak hold and slow falloff.
• Song analysis including BPM (librosa beat tracker), key, scale, and confidence (Albrecht-Shanahan profiles), integrated LUFS (BS.1770), and sample peak in dBFS.
• Cancellable jobs. Cancel mid-pipeline and the runner terminates the active subprocess immediately, deletes the partial job dir, and returns to ready.
• Library panel with folder-based track organisation, drag-and-drop, search, and trash.