CRATEZip, RAR, 7-Zip, or Crate?
General-purpose zippers were built for documents and code. They do shrink an audio session — and then they stop, because a waveform is a wall of random bytes to them. Crate was built for one job: moving audio sessions. It reads the stems, packs them to roughly half the size of a zip, and proves every byte arrived perfectly.
Try it yourself: take a finished multitrack session, zip it, then pack it with Crate. Across the twenty real client sessions in our benchmark, the zip came out between 1.38 and 2.46 times the size of the .crate package. The zip is not doing nothing — it saved a median of 51.5% (per-session range 15–88%). It simply runs out of things to find, because a byte-level compressor never sees the waveform underneath.
Crate doesn't compress bytes. It decodes the audio, re-encodes it losslessly (FLAC for integer, WavPack for float), deduplicates repeated takes and bounces across files, and rebuilds an exact twin on the other end — checked sample-for-sample with SHA-256.
Side by side
| Zip | RAR | 7-Zip | Crate | |
|---|---|---|---|---|
| Understands audio | — | — | — | Yes |
| Packed size, share of the original | 45.2% | 30.9% | 35.1% | 25.2% |
| Proves the copy is bit-perfect | — | — | — | SHA-256 |
| Deduplicates takes across files | — | — | partial | Yes |
| Opens a dropped archive and packs the audio inside | — | — | — | Yes |
| Split into upload-sized volumes | — | Yes | Yes | Yes |
| Recovery data for flaky transfers | — | Yes | — | Yes |
| Free for the recipient to open | Yes | Yes | Yes | Yes |
| Files ever leave your machine | no | no | no | no |
Percentages are the packed size as a share of the original session — lower is smaller. Figures are pooled across the eleven mixed sessions of the current benchmark, every archiver at its strongest setting (zip -9, RAR -m5 -s -md1g, 7-Zip -mx=9, Crate on Smallest), every result restored and compared byte for byte. Per-session ranges are wider — the Impact page carries them lane by lane.
The benchmark
One run, one machine, nothing else running. Twenty real client sessions — mixed, loop-heavy, stem exports and dense live recordings — each packed by Crate on both of its presets and by ten other archiver configurations set for maximum compression, every run restored and compared byte for byte. Sessions are pooled into four material classes so no one session can stand in for the rest. The full tables are on the Impact page, engine by engine.
Why the gap exists
A zipper looks for repeated byte patterns, and a session does hold some: headers, long stretches of silence, whole files that appear twice. That is worth the 15 to 88% a zip finds on audio sessions — about half, at the median — and then the search is over, because the low bits of a 24-bit WAV are noise to it. Crate instead does what an audio engineer would: it reads the actual waveform, stores it in a lossless audio codec, notices when two tracks are the same take (on by default) and — on the Smallest preset — when a bus is the sum of its stems, keeping only what's unique. Then it reassembles a byte-identical copy and proves it.
That's also why Crate can be honest about being lossless: “lossless” isn't a promise on the box, it's a SHA-256 check on every file, every time.
When a zipper is fine
If you're sending a couple of MP3s, a PDF, or a folder of code, reach for zip — it's everywhere and the savings wouldn't matter. Crate earns its place the moment you're moving a real session: many tracks, big WAVs, a slow or expensive connection, and a deadline that can't survive a corrupted upload.
Free to download and to receive. $25 once to pack — no account, ever.