ALS to XML Converter
Convert Ableton Live .als files to readable .xml instantly in your browser. No upload, no server - pure client-side gzip decompression.
Drop .als file here or click to browse
Also supports .adg, .adv, .alc files
About
Ableton Live Set files (.als) are gzip-compressed XML documents. The binary envelope obscures the underlying project structure - track routing, device chains, clip data, automation - making programmatic access or version-control diffing impractical without decompression. This tool performs a real gunzip operation entirely in your browser using the native DecompressionStream API. No data leaves your machine. The resulting XML is the identical document Ableton Live parses internally, suitable for inspection, automated editing, or archival in a human-readable format. Note: this tool does not modify the XML structure. Round-trip integrity (re-compressing to .als) requires matching the original gzip parameters, which Ableton is not strict about.
Formulas
The conversion is a single decompression operation. Gzip wraps the DEFLATE algorithm with a header and checksum.
Internally, the gzip stream begins with magic bytes 0x1F 0x8B, followed by a compression method byte (0x08 for DEFLATE), flags, timestamp, and the compressed payload. The browser's DecompressionStream handles the full RFC 1952 specification natively.
Where CRC32 is the cyclic redundancy check of the uncompressed data and ISIZE is the original size modulo 232. The decompressed output size Sout relative to compressed size Sin follows a typical compression ratio:
Where R is the expansion ratio, typically between 5 and 15 for XML-heavy Ableton projects.
Reference Data
| Property | ALS (Binary) | XML (Output) |
|---|---|---|
| Format | Gzip-compressed XML | Plain-text XML |
| Magic Bytes | 1F 8B (gzip header) | 3C 3F (<?) |
| Typical Size Ratio | 1× | 5−15× larger |
| Human Readable | No | Yes |
| Version Control Friendly | No (binary diffs) | Yes (line-by-line diffs) |
| Ableton Version | All versions (6+) | Same schema |
| Root Element | Ableton with Creator attribute | |
| Encoding | Gzip (DEFLATE) | UTF-8 |
| Contains Audio Data | No - references file paths only | |
| Contains MIDI Data | Yes - embedded in MidiClip elements | |
| Contains Automation | Yes - AutomationEnvelope nodes | |
| Contains Plugin State | Base64-encoded blobs within VstPluginInfo | |
| Max Observed File Size | 50 MB compressed | 500 MB+ decompressed |
| MIME Type | application/gzip | application/xml |
| Can Be Re-compressed | Yes - gzip the XML back to .als | |