Formats & importing · iPhone & iPad
Which audio files
an iPhone will actually play
MP3, M4A, WAV and FLAC all open. OGG, WMA and anything downloaded inside a streaming subscription do not. Here is the whole picture, and the short way to get your own files in.
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- MP3 · M4A · WAVplus FLAC, ALAC, AIFF and CAF
- Whole folderssubfolders included, in one pick
- Always a copyyour original file is never rewritten
Three questions hide inside “will this file play”
People treat an audio file as one thing with one name. It is really three things stacked, and any one of them can be what stops you.
The extension is the last part of the filename. It tells you which box the audio is packed in and almost nothing about the audio itself.
The codec is the format of the sound inside that box. This is where the confusion starts. A file ending in .m4a can hold AAC, which is compressed and has thrown detail away, or it can hold ALAC — Apple Lossless — which has not. Same extension, same icon in Files, very different file. Both open on an iPhone, so in this one case the confusion is harmless.
The lock is whether the file is even allowed to leave the app that made it. A song downloaded inside a streaming subscription is an ordinary-looking file that no other app on the phone is permitted to read. That is the one that actually catches people out, and no converter fixes it.
Get those three straight and the rest of this page is short.
What an iPhone opens without any help
iOS carries its own decoders, so an app does not have to ship one. Everything on this list is readable by the system itself, which is why these formats work in one app and then work in the next.
- MP3 — the one that never argues. Lossy, universal, and what most older files and most download stores land in.
- M4A (AAC) — what purchases and most modern downloads use. At the same file size it holds up better than MP3, which is why it replaced it.
- M4A (ALAC) — Apple Lossless, in the same container. Identical to the disc it came from, at roughly half the size of a WAV.
- WAV — uncompressed. Nothing thrown away and nothing packed, which makes it much the largest of these. Sensible for a few masters, heavy for a whole library.
- FLAC — lossless and compressed, the format Bandcamp and Qobuz hand you when you ask for the good version. iOS has decoded FLAC since iOS 11, and it is not a second-class citizen here: Y2K Player reads a FLAC picture block for cover art exactly the way it reads an ID3 tag on an MP3.
- AIFF and CAF — Apple’s own uncompressed formats, common in anything that came off a Mac or an audio interface. Recognised on import like the rest.
Nothing above needs converting. If your files are already one of these, the entire problem is moving them onto the phone.
What will not open, and what to do instead
The list of formats an iPhone cannot read is short, for a boring reason: the system never shipped a decoder for them, so no app can open one without bundling a decoder of its own.
- Ogg Vorbis (.ogg) and .opus — common on Linux, in game rips and in older downloads. Neither opens.
- WMA (.wma) — what a Windows rip from the mid-2000s produced. Also does not open.
- Protected downloads — the offline files kept inside a streaming app. Those are tied to the app that made them by design.
For the first two the fix is one conversion on a computer, before the files ever reach the phone. Send them to FLAC if the source was lossless and you want it to stay that way, or to M4A at 256 kbps if you would rather have the space back. Converting an already-lossy file — an OGG into an MP3 — loses a little more each time, so do it once and keep the result rather than re-converting later.
For the third there is nothing to fix, and it is worth being blunt about it: the way to have a song as a file is to buy it as one. Stores that sell you the actual download, your own rips, recordings, and bounces out of whatever you make music in are all fair game. A subscription is not.
The short version
- Plays: MP3, M4A with AAC inside, M4A with ALAC inside, WAV, FLAC, AIFF, CAF.
- Does not play: OGG, OPUS, WMA, and anything downloaded inside a streaming subscription.
- .m4a is a container, not a codec. It can hold AAC or Apple Lossless, and both are fine.
- Video counts as a source: MP4, MOV and M4V go in and the audio track comes out as a track.
- Y2K Player registers itself for public.audio and public.movie, which is why it appears under “Open with” and in the share sheet for both.
- Every import is a copy. The file you picked is never rewritten.
Getting them onto the phone
Most of this is deciding what needs converting. The import itself is one pick.
- Find out what you actually haveOn a computer, sort the folder by kind or by extension. You are looking for anything that is not MP3, M4A, WAV, FLAC, AIFF or CAF — usually a small handful of OGG or WMA files left behind by an older machine.
- Convert only the straysLeave the ones that already work alone; every conversion of a lossy file costs a little more quality. Send the strays to FLAC if the source was lossless, or to M4A at 256 kbps if you would rather have the space back.
- Put them somewhere the phone can reachiCloud Drive, Dropbox, a USB drive plugged into the phone, or a sync from a computer — anything that turns up in the Files app. Keeping them in one folder makes the next step a single tap.
- Import the folder, not the filesTap Add, choose Import Songs, and pick the folder itself. Every audio file inside it is imported, subfolders included. A large folder takes a moment because each file is copied rather than linked.
- Check what did not arriveAnything missing is either a format the phone cannot read or a protected download. The Music Library route says so outright: protected streaming copies are counted and reported instead of quietly disappearing.
What Y2K Player does with them
It is a local player. It opens files you already own and streams nothing, which makes the import path the whole relationship — so it is worth knowing exactly what happens to a file on the way in.
There are three routes in the Add sheet. Import Songs opens Files and takes individual tracks or a whole folder; pick the folder itself and every audio file inside is imported, subfolders included, in one go. From Music Library reaches the songs synced or purchased on this iPhone, and protected streaming copies are counted and reported rather than quietly dropped. Import Video Sound takes a clip out of Photos and pulls its audio track in as a track, leaving the video where it was.
There is a fourth that people find by accident, and it is the fastest one. Because the app is registered as an owner of public.audio, it appears under “Open with” and in the share sheet everywhere on the phone: Files, Mail, a messaging app, an AirDrop that has just landed. Send a song to Y2K Player and it is in the library.
What happens on the way in
Each file is copied into the app’s own folder, so it is that copy which gets played and yours which stays exactly where it was. Title, artist and album are read from the tags when they exist, which is how albums group themselves without anyone doing anything. Embedded cover art is pulled out and shrunk to a 600-pixel JPEG, so a library of high-resolution covers does not cost a gigabyte on its own. A waveform is measured in the background, so the waveform screen is instant the first time you open it rather than thinking about it.
Nothing afterwards touches the audio either. Speed, pitch and effects are settings remembered per song, and even renaming a track renames the library entry and leaves the file alone.
A library does not have to be tidy
A reasonable worry is that mixing formats and sample rates will cause trouble: a 44.1 kHz MP3 followed by a 48 kHz WAV, a mono voice memo after a stereo master. It does not. The player reads each file’s own format as it loads and rebuilds its audio chain around it, so one song can follow another at a different rate without a click in between.
What is worth tidying is the tags rather than the formats. Titles and artists come from what is written inside the file, so a folder of tracks called 01, 02, 03 arrives in the library called 01, 02, 03. Both can be edited afterwards, and editing them there never rewrites the file.
Questions about formats and importing
Answered here rather than after you have installed anything.
Does an iPhone play FLAC?
Yes. iOS has decoded FLAC since iOS 11, and Y2K Player imports FLAC files like any other audio file — including reading the cover art out of the file’s own picture block, the same way it reads an ID3 tag on an MP3. Nothing needs converting first.
What is the difference between M4A and MP4?
They are the same container with different contents. An .mp4 usually has video in it; an .m4a is the audio-only version of the same box. Both go into Y2K Player — if you hand it an MP4, it takes the audio track out and adds that to the library as a track, leaving the video where it was.
Is .m4a the same as AAC?
Not quite. AAC is the compression; .m4a is the box it usually travels in. That same box can also hold ALAC, which is Apple Lossless and is not compressed in a way that loses anything. Both play, so the distinction only matters when you are deciding what to keep.
Can I import songs I downloaded inside a streaming app?
No, and no app can. Those downloads are locked to the app that produced them. Y2K Player plays audio files you own: purchased downloads, your own rips, recordings, and anything you have bounced out of a music app yourself. If a protected item is picked from the Music Library, it is counted and reported rather than failing silently.
Why will my .ogg or .wma file not open?
Because iOS has no decoder for either. It is a platform limitation rather than an app one, which is why they fail everywhere on the phone and not just here. Convert them once on a computer — to FLAC if the source was lossless, to M4A otherwise — and the converted files behave normally.
Will importing change or move my original files?
No. Every import is a copy into the app’s own folder; the file you picked stays exactly where it was and is never rewritten. Speed, pitch and effects are all stored as settings attached to the song, and even renaming a track only renames the library entry.
Can I import a whole folder at once?
Yes. Pick the folder itself rather than the files inside it and every audio file in it is imported, subfolders included. It is the fastest way to move a music collection over, and a large folder simply takes a while because each file is copied.
Can I get the audio out of a video I already have?
Yes. MP4, MOV and M4V files can be imported directly, or picked from Photos through Import Video Sound. The audio track is pulled out and added to the library as an ordinary track. The video itself is not modified or deleted.
Does importing need an internet connection?
No. Importing, playing, changing speed and pitch and exporting all happen on the device. Airplane mode changes nothing except that you cannot buy anything.
What formats does it export to?
M4A (AAC) or WAV for audio, and MP4 for video. There is no MP3 export, because iOS ships an MP3 decoder but not an MP3 encoder — AAC at the same bitrate is the better file anyway. Free audio exports render the song’s first 30 seconds; video exports are full length on both tiers.
Does it work on iPad?
Yes, on iPhone and iPad, from iOS and iPadOS 18 onwards.
Is Pro a subscription?
Free to use. Pro is one payment — forever. What Pro adds lays out the difference.
Where to go next
- How to choose a playerWhat separates a local player from a streaming app, and which one you actually want.Open →
- Playing with no connectionEverything happens on the device, including the parts you would expect to need a server.Open →
- Slow a song downOnce the file is in, this is the first thing most people do to it.Open →
- Audio for editsWhere the files come from, and how to prepare one for a video.Open →
Bring your own files.
MP3, M4A, WAV, FLAC and the rest, a folder at a time, played and reshaped entirely on the phone.
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