StemForge

Overview

StemForge is ranked #19 of 22 in AI music remixing tools on Specifiction. It runs on Linux, macOS, Self-hosted, Web, Windows. There is a free plan.

Compared on AI music remixing tools

Remix workflow

bothgithub.com

Export formats

wav, flac, mp3, ogggithub.com

Facts

Product

StemForge is an open-source, GPU-accelerated audio workstation for stem separation, MIDI extraction, audio generation, and song composition that runs locally in a browser.github.com · 4 Oct 2026

Privacy

The project says audio stays on the user's computer and no internet connection is required after initial model downloads.github.com · 4 Oct 2026

Stem separation

Demucs and BS-Roformer separate audio into vocal, drum, bass, other, guitar, and piano stems, with automatic engine and model recommendations based on spectral analysis.github.com · 4 Oct 2026

MIDI

StemForge extracts MIDI from instrument stems with BasicPitch and vocal melodies with faster-whisper and pitch tracking, and can send MIDI to hardware synths through Web MIDI.github.com · 4 Oct 2026

Audio generation

The Synth tab uses Stable Audio Open for text-conditioned audio generation up to 600 seconds, with optional audio or MIDI conditioning.github.com · 4 Oct 2026

Song composition and voice conversion

The Compose tab uses AceStep for song generation and RVC for voice conversion, with 14 built-in voices and a HuggingFace model browser.github.com · 4 Oct 2026

Mixing and export

The Mix tab combines audio stems, MIDI-rendered tracks, synth outputs, and composed songs; exports support WAV, FLAC, MP3, and OGG, individually or as a ZIP archive.github.com · 4 Oct 2026

Integrations

The documented workflow connects Separate, MIDI, Synth, Compose, Mix, and Export tabs so outputs can flow between pipelines; MIDI Out connects to hardware synths via the browser's Web MIDI API.github.com · 4 Oct 2026

Platforms

The project documents Linux and macOS support, Windows use through WSL, and access through a web browser; Apple Silicon uses MPS, while AMD GPU support via ROCm is untested on real hardware.github.com · 4 Oct 2026

Requirements and limits

The documented setup requires Python 3.12, FFmpeg, and FluidSynth with a GM soundfont; NVIDIA GPU acceleration requires driver 580 or newer, while CPU-only operation is significantly slower.github.com · 4 Oct 2026

Model downloads

Models download lazily on first use; the Compose tab's AceStep models require about 20 GB, and the Stable Audio Open model requires HuggingFace license acceptance and authentication.github.com · 4 Oct 2026

MIDI browser support

MIDI Out requires Chrome or Edge and a secure browser context; the project documents HTTPS or localhost as supported secure origins.github.com · 4 Oct 2026

Where it ranks on Specifiction

• Best AI Music Remixing Tools in 2026#19 of 22

Sources

• github.com/tsondo/StemForge· checked 4 Oct 2026