System requirements

macOS — the current build

macOS 11 Big Sur or later. This is what the app bundle declares as its minimum system version.
Apple silicon. The release is built for aarch64-apple-darwin, and the launch macOS build is Apple silicon only. A Universal build that also runs on Intel Macs has been built and passes CI; it is planned for a later release and is not available now.

Windows — at launch

Windows is confirmed as a launch platform. The build exists and is in release validation, so nothing is published for download yet, and these are the facts that are settled rather than a final list.

Windows on x64. There is no ARM64 Windows build.
A per-user installer. It installs into your own user profile and does not need administrator rights.
Minimum Windows version: not yet confirmed. It will be published here before launch, and not guessed at before then.

On every platform

Disk space for the index and artwork cache, not for your music — Digr never copies your files. A large library's index and cached covers are measured in tens of megabytes, not gigabytes.
No network required to run, scan or play. A local network is needed only to cast.
No account. There is no sign-in and no user record, and there is no plan for Digr Free to need one. The current alpha also has no licence key of any kind — that is a statement about this build, not a permanent commercial promise: Digr Pro is priced, and a paid tier will eventually need some way to prove you paid for it.

Audio formats

Two different lists, because indexing a file and decoding it are two different jobs.

Indexed with full metadata: MP3, FLAC, ALAC, M4A, AAC, WAV, OGG. Tags, artwork and duration are read and the track is filed into your library whatever your machine can play.
Plays locally on macOS: MP3, FLAC, ALAC, M4A, AAC, WAV. Decoding is the operating system's job in this build, so OGG depends on your machine's codecs. When a file can't be decoded, Digr says so on that track rather than skipping it in silence. A native decoder that lifts this limit is on the roadmap.
On Windows, decoding is the system WebView's job in the same way. Which formats it plays is part of release validation, and this page will list them once they are tested.
Cast: whatever plays locally is streamed to the device as the original file. No transcoding step, silent or otherwise.

Casting

Google Cast — Chromecast, Google Home speakers and Cast speaker groups. It is the only protocol implemented today.
Same network. Discovery uses mDNS and the device fetches audio from a server running on your computer, so both need to be on the same LAN. Client isolation on a guest network will prevent it.
No AirPlay, DLNA/UPnP or OpenHome today. All three are on the roadmap rather than ruled out — they are simply not in this build.

Not supported today — but planned

None of these is in a release you can install, and until one is, this page will not claim support for it.

Intel Macs. A Universal build is complete and passes CI. It is planned for a later release, not the launch.
Linux. Planned for a future release. Digr is launching on Windows and macOS first, with Linux support on the roadmap.
AirPlay, DLNA/UPnP and OpenHome. Future network-audio work; Google Cast is what ships now.
Metadata and tag editing. Digr reads your files and never writes to them in this build. Explicit, reviewable, undoable tag editing is planned.

Not planned

iOS and iPadOS. Not on the roadmap.
Streaming services and cloud libraries. Not an omission — the point.
Network-attached libraries unmounted mid-scan. A share that disappears during a scan is handled safely rather than supported: the root is preserved, not pruned. Proper NAS reconnection is on the roadmap.

The full picture — what is implemented, what is planned at each horizon, and what is genuinely ruled out — lives on the features and roadmap page.