Send large audio files in studio quality

Why audio files get so big

Uncompressed audio size is simple arithmetic: sample rate × bit depth × channels. A three-minute stereo master is manageable, but stems and multitrack sessions multiply it quickly.

An album mastered at 24-bit / 96 kHz is a few gigabytes; the stems for a single song can pass 1 GB; a podcast season recorded on separate tracks easily reaches tens of gigabytes. Email stops at 20 to 35 MB per message (as of October 2026), barely one CD-quality song.

How to send audio files without losing quality

Quality is lost when a service re-encodes your files: messaging apps convert voice and audio to lossy formats, and streaming platforms transcode uploads. Even a well-made MP3 throws away information you cannot get back for mixing or mastering. The rule is simple: send the exact files you exported, through a channel that does not touch them. Transfr stores and delivers your files byte for byte, so a 32-bit float WAV arrives as a 32-bit float WAV.

1. 1

   Step 1

   Export and name your files

   Bounce stems from the same start point, and name them clearly: song, part, tempo, sample rate (“Song_Bass_120bpm_48k.wav”).

2. 2

   Step 2

   Drop the folder on Transfr

   Open Transfr and add the files or the whole session folder, up to 100 GB per transfer. Folder structure is kept.

3. 3

   Step 3

   Turn on comments for feedback

   Listeners can then leave a note at an exact time in a track: “vocal too loud at 1:42”.

4. 4

   Step 4

   Send the link

   Copy it into your usual chat, or email up to 10 people: artist, producer, mixer, label.

Listen and comment before downloading

On the download page, audio files play in the browser, so an artist can listen to a new mix on their phone without downloading a gigabyte of stems. With comments on, they pause, type a note, and the comment is pinned to that moment of the track. Clicking it jumps back to the same second. You get an email for each new comment.

WAV, AIFF or FLAC: what should you send?

Ask what the recipient expects. Mix and mastering engineers usually want WAV or AIFF at the session’s sample rate, never upsampled. Distributors and labels have their own delivery specs. Since size is no longer the constraint with a 100 GB link, send what the job requires rather than what fits.

Sending stems and full sessions

• Stems: export each one from bar 1, even if it starts later, so they line up when imported.
• Sessions: use your DAW’s collect or save-as-copy function so every audio file used by the project is in one folder, then send that folder.
• Tempo and key: put them in the file names or the transfer message.
• Zip or not: WAV compresses a little in a ZIP, but FLAC does much better if your collaborator accepts it. For sessions, sending the folder works: Transfr keeps the tree, and “download all” gives one ZIP with the same structure. See sending a folder.

Podcasts, audiobooks and field recordings

Spoken-word projects are long rather than dense. A one-hour podcast recorded with four microphones at 24-bit / 48 kHz is about 2 GB of mono tracks before editing; an audiobook delivered chapter by chapter can be several gigabytes; a day of field recording on a multitrack recorder fills a memory card.

• Editors can send the raw tracks to a producer in one transfer, organised by episode.
• Hosts can collect guests’ local recordings with a request link, without asking them to create an account. See receiving large files.
• Clients can review a cut in the browser and leave timestamped notes instead of writing “around the middle”.

For a sense of how long a big upload takes on your connection, see sending 10 GB.

Unreleased music: keep it private

A leaked link to an unreleased album is a real risk. Add a password, set a short expiry, and limit downloads to the number of people who need the files. For the most sensitive material, turn on end-to-end encryption: the files are encrypted on your computer before upload, and Transfr never stores the key. With Transfr Pro, download tracking shows when and from where each file was opened or downloaded.

Musicians, producers and studios will find a full workflow in sending music files. To collect recordings from a band or guests, create a file request: everyone uploads to the same link.