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)
Upload stereo PCM WAV files from Upload or directly on a release.
ALTOSPIN stores your original WAV master and automatically creates an MP3 stream for in-browser playback. Only uncompressed WAV is accepted for upload — MP3, FLAC, AIFF, and other formats are not supported at this time.
Format: PCM WAV (.wav) 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 WAV master
After upload, the platform encodes a streaming MP3 at 192 kbps, 44.1 kHz stereo for playback in the catalog and player. Your original WAV is preserved for download and distribution exports.
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 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, catalogue number, 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 MP3 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. Track download: Download individual WAV or MP3 masters from a track's detail page. Release download: Export an entire release as a ZIP (WAV or MP3) with embedded metadata and artwork from the release page. 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.
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 files are supported" — Re-export as PCM WAV. 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 — Keep the file at 10 MB or under. Re-export as JPEG or WebP at high quality if a PNG exceeds the limit.
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.