A flight-safe music library

Streaming downloads are a licence with a timer on it. Spotify's offline files expect the app to check in roughly every thirty days, Apple Music's downloads want periodic verification, and both fail in the same place — somewhere with no signal, after a stretch without one. Files you own do not expire, because there is nothing to verify.

Set this up the day before, not at the gate.

The short version

• Test in airplane mode before you leave. Two minutes, and it is the only real test.
• Files on the device have no licence, no check-in and no expiry.
• Wired headphones and an adapter, if the seat has a jack and your battery matters.
• Sleep timer stops the music without stopping the flight.
• A long trip is a good reason to finally carry your own library.

The test, before you go

Do this at home, a day early.

1. Airplane mode on. Wi-Fi off — actually off, not "not connected".
2. Open the app.
3. Play something you have not played today.
4. Skip to a different album.
5. Lock the phone. Check it keeps playing.
6. Leave it a few minutes and come back.

Anything that shows a spinner, asks you to sign in, or plays one track but not the next is going to fail you at altitude. This test catches the expired-licence problem, which otherwise only ever reveals itself when there is no way to fix it.

Why files behave differently

There is nothing to check.

A local player opens a file. No account, no subscription, no entitlement, no server. Refrain in particular makes no network requests at all in normal use, so there is no code path that can fail when the network is gone — search, browsing, playlists, lyrics, the equalizer and the visualizers all run on the device.

The distinction is worth understanding once because it explains every version of this problem: what "offline" means in different apps.

Packing a library

Take more than you think. A long-haul flight, a connection and a hotel with bad Wi-Fi is twenty hours. Ten albums is not enough.

Take things you know. Long flights are a bad time to discover music. Familiar records you can sleep through are worth more than a carefully curated new list.

Watch the size. MP3 at 5–10 MB per track means a hundred albums in roughly 10 GB. FLAC is three times that. For a trip, convert lossless to MP3 or AAC and save the space for photos — the arithmetic.

Build the playlists before you go, not on the plane in the dark. Something for takeoff, something for sleeping, something for the last hour when you are done with everything.

Charge everything, and take a battery pack. Audio playback with the screen off is very cheap on battery, which is a real advantage over watching things.

Getting it on there

If your music is on a computer at home, do it the night before.

Cable. Fastest for a large batch. Plug in, open the phone in Finder, Files, drag the folder onto Refrain.

Wi-Fi transfer. No cable needed — Refrain shows an address and a code, you open the address in a browser on your Mac and drag files onto the page. The guide.

From a cloud folder. If your library is in iCloud Drive or Dropbox, make sure it is actually downloaded rather than a placeholder, then import with Add → Choose a folder. This is the classic trap: files that look present are references until something downloads them, and a placeholder at 35,000 feet is nothing at all.

In the air

Wired headphones if the seat has a jack. Bluetooth is fine and it is another thing to charge, another thing to lose down the side of a seat, and useless with the in-flight entertainment.

Sleep timer. 5 to 60 minutes, or stop at the end of the current track. Set it, fall asleep, and the music stops on its own rather than playing to an empty pair of ears for nine hours.

Lock screen controls work normally, so the phone can stay in the seat pocket.

Coming home with the habit

The useful side effect of setting this up for one trip: you now have your own library on your phone, and it keeps working. In tunnels. In a country where you have no data plan. In the years after whichever service you were renting from changes its terms.

That last one is not hypothetical. Udio disabled downloads of everything generated on it in October 2025. Bandcamp has changed hands twice. Every free cloud tier has shrunk at some point. A folder on a drive you own is the only copy whose terms cannot change.

What this doesn't do

• No streaming, so nothing new arrives while you are away.
• No sync, so the iPad in your bag has its own separate library.
• No CarPlay for the drive at the other end.
• No resume position on long files, so an audiobook or a two-hour set restarts from zero.

Related

• iPhone music apps that work with no internet
• Which audio formats play on iPhone
• An offline music player that doesn't want an account
• All guides · Refrain