Upload your first track

The fast path

1. Sign in to app.soundassist.online.
2. Click Upload a new track in the menu, or drop an audio file anywhere on the front page.
3. Fill in the title (everything else is optional).
4. Follow the steps to the end.

That's it. The track now has a private listen link you can share. Only the people you send the link to can open it.

What formats are accepted

Lossless masters (kept bit-exact, also streamed losslessly):

• WAV, FLAC, AIFF, ALAC

Lossy masters (kept as-is, streamed at source bitrate):

• MP3, M4A, AAC, OGG, Opus

We don't accept these as masters: video formats, executables, archives (ZIP, RAR). For project files / stem packs see the Folders page; those go through the attachments flow, which accepts a wider range.

File size limits

• Per-track ceiling: 500 MB.
• Per-account ceiling: depends on your plan (5 GB on the free one, more on a paid one).

A 500 MB cap covers:

• ~3.5 hours of MP3 320kbps (DJ set length)
• ~15 minutes of 24-bit 96kHz lossless (a track in mastering quality)

If you need to send something bigger, split it across multiple tracks or use the folder sharing flow which has no per-file cap (only the account total).

What happens while we prepare the stream

After upload we run two passes:

1. Magic-byte verification. We read the first few bytes of the file to confirm it's actually the format you said it was. If a .exe was renamed to .wav, this is where it gets rejected.

2. FLAC stream encode. For lossless masters we encode a FLAC stream alongside the original so listeners get bit-exact playback without downloading 200 MB. Lossy masters skip this step and stream directly.

You can play the track as soon as the upload completes; the second pass runs in the background and doesn't hold you up.

BPM + key detection

Tracks under 10 minutes get an automatic BPM + musical-key analysis. The detected values show on the track row + on the listen page. Values are estimates: often spot-on for clear-cut genres (house, hip-hop) and less reliable for atmospheric / ambient material.

When we can't tell, the field stays empty rather than carrying a confident wrong answer. See BPM and key detection.