Ableton Live Set Downgrader

Local/offline tool that creates a new downgraded copy of an Ableton Live .als Set intended for an older Live version.

Original files are never modified.

Open source (MIT): github.com/montronedsp/alsconverter

Privacy

This project does not collect any data. Conversion runs entirely on your machine. There is no account, telemetry, analytics, or cloud upload in the CLI, GUI, or in-browser tool.

Status (Milestone 1)

Path	Status
Live 12 → Live 11	EXPERIMENTAL (static validation + public evidence)
Live 12.x → earlier 12.x	RESEARCH
Live 11 → 10 / 10 → 9	RESEARCH (not implemented)

Safety

• Never overwrites the source .als
• Writes only to output/ (or an explicitly chosen destination)
• Never silently overwrites an existing destination
• Never launches Ableton, touches samples, plugins, or preferences
• Treats every real Ableton project as read-only

Install

cd ableton-downgrader   # or this repository root
python -m pip install -e ".[dev]"

Commands

# Inspect a Set (read-only)
alsdowngrade inspect "path/to/Session.als"

# Compatibility / risk report
alsdowngrade analyze "path/to/Session.als" --target 11.2

# Structural XML diff
alsdowngrade diff "older.als" "newer.als"
alsdowngrade diff "older.als" "newer.als" --normalize

# Convert Live 12 → Live 11.2 (default; use --target for other 11.x builds)
alsdowngrade convert "path/to/Session.als" --target 11.2

# Other Live 11 point releases
alsdowngrade convert "Session.als" --target 11.2.7 --mode compatible
alsdowngrade convert "Session.als" --target 11.3 --mode compatible
alsdowngrade convert "Session.als" --target 11.1 --mode compatible
alsdowngrade convert "Session.als" --target 11.0 --mode compatible

Windows GUI

python -m pip install -e .
alsdowngrade-gui

Build a portable Windows folder (PyInstaller):

powershell -File scripts/build-windows.ps1

Output: dist/ALSConverter/ALSConverter.exe

Prebuilt Windows release: v0.1.0

NO WARRANTY / NO GUARANTEE. Provided as-is. Converted Sets may fail to open or lose features. Keep backups. Not affiliated with Ableton AG.

Example output name:

Session.als → Session_Live11_2_11_downgraded.als

What this is not

This is not a header-only Creator string patcher. Conversion uses an explicit transform-rule engine (metadata remapping, known Live-12-only structure handling, routing path normalization) with validation layers. See docs/.

License

MIT. Third-party references are documented in docs/THIRD_PARTY.md.