Lossless archiver for Windows & Linux
Archive huge folders at GPU speed.
MCZ cuts files into content-defined chunks on the GPU, compresses them across every CPU core, stores identical chunks once and verifies every byte on the way back out.
Free for personal use. Organisations: 30-day evaluation, then one licence per computer.
> mcz c project.mcz D:\Projects\CitySample scan backend: CUDA 111 GB in, deduplicated, verified > mcz t project.mcz all chunks OK (CRC32 + XXH64)
GPU chunking
Chunk boundaries are found on the GPU (CUDA or Direct3D 11), with a CPU fallback. Every backend produces identical archives.
Parallel pipeline
Lock-free ring buffers feed a pool of compression workers; a single serializer writes the archive in order.
Deduplication
Identical chunks are stored once, across files and folders, which pays off on builds, assets and backups.
Verified, byte for byte
Every chunk carries CRC32 and XXH64 and every file a whole-file hash. Extraction re-checks all of them.
Command line and GUI
mcz c / x / t / l for scripts and scheduled jobs; a desktop app for everyone else.
Offline licensing
Keys are verified on the computer itself. No licence server to run, no phoning home.
Licensing a fleet takes three steps
- Collect Machine IDs. Run our PowerShell script across your PCs (GPO, Intune or remoting) to get a CSV of PC names and Machine IDs. How
- Upload and pay. Upload the CSV, check the price and pay by card through Stripe. You get a VAT invoice.
- Download your keys. You get a CSV back with one licence key per PC, ready to deploy with
mcz license <key>.