Help & requirements
File formats, size limits, and upload guidelines for ALTOSPIN. These match what the platform accepts during upload — if a file is rejected, check the details below.
Audio masters (WAV / AIFF)
Upload stereo PCM WAV or AIFF files from Upload or directly on a release.
ALTOSPIN accepts uncompressed stereo PCM WAV or AIFF for masters. AIFF is converted to WAV on upload, then archived as WavPack with an Opus stream for in-app playback. MP3, FLAC, and other formats are not supported as uploads.
Format: PCM WAV (.wav) or AIFF (.aiff / .aif) Channels: Stereo (2 channels) only Sample rate: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, or 192 kHz Bit depth: 16-bit, 24-bit, or 32-bit Minimum length: 2 seconds Maximum file size: 500 MB per master
After upload, the platform encodes an Opus stream for catalog playback. Your lossless master is preserved for download. MP3 downloads are encoded in your browser when you request them.
Track versions: You can upload alternate versions (e.g. instrumental, radio edit) linked to a parent track from the track detail page.
Release artwork
Square cover art attached to a release — not per individual track.
Artwork requirements follow common digital distribution (DSP) standards so your covers are ready for release packaging and sharing.
Formats: JPEG, PNG, or WebP Aspect ratio: Square (width must equal height) Dimensions: 3,000 × 3,000 px minimum — 6,000 × 6,000 px maximum Maximum file size: 10 MB (you’ll be asked before any size compression) Color space: RGB (sRGB recommended)
A smaller WebP thumbnail is generated automatically for catalog lists and previews. Upload artwork from a release's detail page — drag and drop or click the artwork area.
Tip: Export at 3,000 × 3,000 px or higher at 72–300 DPI. Avoid text or logos placed too close to the edges; many platforms crop artwork slightly when displayed as a circle or rounded square.
Releases & metadata
Group masters into releases and add distribution metadata.
Group masters into releases (Single, EP, or Album) and add distribution metadata as needed.
Release types: Single, EP, or Album Track metadata: Title, genre, subgenre, ISRC (12-character code), and release/production versions Release metadata: UPC, cat. nr., label, genre, release date, description, streaming links, and distributor information Contributors: Credit mix engineers, mastering engineers, and other roles at the release level
ISRC codes must be exactly 12 alphanumeric characters (dashes and spaces are stripped automatically). Example format: USRC17607839
Playback & downloads
Streaming, waveform controls, and download options.
Streaming: Tracks play back as Opus in the browser. Audio loads on demand — full files are not preloaded. Waveform: Click or drag on a waveform to seek. If nothing is playing yet, clicking a position starts playback from there. Dock meters (Peak meters): Default is sample-peak dBFS. Setup → Meter details → Peak scale can switch to true peak (dBTP, 4× oversample, scale to +3). True peak only *activates* on lossless playback (local vault or master WAV in the wave editor); Opus/stream stays on sample peak even if True is selected. Filled bar = peak; yellow markers = RMS; thin line = peak hold (factory default 1s; Off / 1s / 2s / 3s in Setup). Over bars light in the last 1 dB (−1 / −0.5 / ~0); Clip hold latches on the 0 mark of the active scale (factory default Off). Zones palette is the factory default; red starts at −1 dB. In Setup, choose Peak meters or Loudness — these are separate from public-page VU meters. Public VU meters: Share pages use cosmetic VU dials calibrated so 0 VU = 0 dBFS (needles follow sample peak so full-scale sits near 0, not ~−3 from RMS). Optional LED Peak Meters are separate sample-peak strips (−60…0 dBFS) that fill fully to the right at 0 dBFS — not VU-scaled. Wave editor meters: Follow your dock Setup (including Peak scale). Captions show dBFS or dBTP for the active detector; true peak needs lossless (master WAV / local vault). Track download: Download individual WAV or MP3 masters from a track's detail page. MP3 is encoded in your browser from the lossless master when needed. Release download: Export an entire release as a ZIP from the download menu — tagged WAV, raw WAV, or MP3 (320 / 192 kbps) with embedded metadata and artwork. On mobile, individual signed download links are provided instead.
Player keyboard shortcuts
Work anywhere on the page while a track is loaded.
Shortcuts are ignored while you're typing in a text field, dropdown, or when a button has focus, so they won't interfere with editing metadata or forms.
Space: Play / pause ←: Rewind 5 seconds →: Forward 5 seconds ↑: Previous track ↓: Next track
Previous / next track moves through the current playlist: - All tracks on a release page (in track order) - The filtered masters list on your dashboard (cards or table view) - Tracks in an expanded release row on the Releases catalog table (after you start playback from that release) - Public share pages for shared releases
At the first or last track in the list, previous and next do nothing — playback does not wrap around.
Catalog controls
Expand, collapse, and navigate nested rows in Releases and Masters catalogs.
On the Releases and Masters catalogs, rows with nested children (tracks or versions) can expand or collapse.
Click a chevron or version count: expand or collapse that row only.
⌥ Option / Alt + click the same control: expand or collapse all rows (same idea as Finder).
⇧ ] (Shift + ]): expand all rows ⇧ [ (Shift + [): collapse all rows
These shortcuts are ignored while you're typing in search or other fields. On Masters, expand/collapse all is unavailable while list editing is unlocked (families stay open for editing).
Upload limits & troubleshooting
Rate limits and common upload issues.
Audio uploads: Up to 10 per minute per account Artwork saves: Up to 10 per minute per account
Common issues:
"Only WAV or AIFF files are supported" — Re-export as PCM WAV or AIFF. Compressed formats (MP3, AAC) cannot be uploaded as masters.
"WAV must be stereo" — Convert mono or surround mixes to 2-channel stereo before upload.
"Unsupported sample rate / bit depth" — Use one of the supported sample rates and bit depths listed in the Audio masters section.
Artwork dimension errors — Resize to a square between 3,000 and 6,000 pixels per side. Non-square images are rejected.
Artwork too large — If a file is over 10 MB, you’ll be asked to proceed with near-lossless JPEG compression at the same resolution. Cancel if you’d rather export a smaller file yourself.
Upload stuck or slow — Large WAV files are transcoded in your browser before upload. Keep the tab open until the progress bar completes. A stable connection helps for files approaching the 500 MB limit.
Account & privacy
Account settings, privacy, and data handling.
Your catalog is private to your account. Manage your artist profile, email, and password under Settings. You can delete your account and all associated files from the same page.
See our Privacy policy and Terms of service for more on data handling.
Need more help?
If something isn't working as expected, send us a message with the file type, approximate size, and any error message you see.