File Extension Guide📖 What is an ALAC File?
An ALAC file is a piece of music or sound saved with the Apple Lossless Audio Codec, Apple's way of shrinking audio without throwing any of it away. Because it is lossless, the sound you get back is an exact copy of the original recording, just stored in a smaller file.
ALAC stands for Apple Lossless Audio Codec, and the important word there is lossless. Many everyday audio formats save space by quietly discarding parts of the sound you are unlikely to notice, which is why they are called lossy. ALAC takes a different path, packing the audio down in a way that can be perfectly unpacked later, so nothing is lost between the original and what you hear. Apple built it in 2004 to give its devices high quality audio that still took up less room than a raw recording.
One point causes a lot of confusion, so it is worth stating early. ALAC is a codec, a method of encoding sound, rather than a file type of its own, so the audio is almost always kept inside a standard Apple audio file ending in .m4a. You will sometimes see the .alac extension, but it is far less common and often just a renamed .m4a. Whichever name it carries, the file holds the same thing, a lossless recording ready to play on Apple devices and many other players.
Key Characteristics
- Lossless audio with no quality lost
- Made by Apple for its devices
- Usually a .m4a file, not .alac
- Smaller than a raw recording
Good to Know
- ALAC means Apple Lossless Audio Codec
- A codec, not a container of its own
- Rivals FLAC, with matching quality
- Open source and free since 2011
⚡ Quick Facts
| Full Name | Apple Lossless Audio Codec |
| Usual Extension | .m4a, sometimes .alac |
| Container | MP4, the standard Apple audio file |
| Compression | Lossless, no quality lost |
| Developer | Apple |
| Introduced | 2004, open source since 2011 |
| Audio Depth | Up to 32-bit, high sample rates |
| Main Rival | FLAC |
🎵 What Lossless Means
The whole appeal of an ALAC file rests on one idea, that the compression loses nothing. It is worth seeing exactly what that means and why it matters.
When audio is compressed in a lossless way, the file is made smaller but every detail is kept, so that decoding it gives back sound that is identical to the original, matching the source bit-for-bit down to the last PCM sample. This is the opposite of lossy compression, used by formats like MP3, which permanently removes parts of the sound to save more space and can never fully restore them. Think of lossless as folding a letter to fit an envelope, where unfolding gives you the exact same page, while lossy is more like summarising the letter, which saves room but loses the original wording. For casual listening on cheap earphones the difference can be hard to hear, but for a serious music library, for archiving CDs or for good headphones, lossless keeps the recording at full fidelity. ALAC typically brings a track down to around half its raw size while preserving all of that detail.
🏷️ Why .m4a, Not .alac
Newcomers often expect an Apple Lossless file to end in .alac, then find it named .m4a instead. This is not a mistake, and the reason goes to the heart of how the format works.
An extension usually names the container that holds the audio, not the method used to encode it. Apple Lossless audio is placed inside the standard MP4 audio container, whose files end in .m4a, so that is the extension you see. The same .m4a container is also used for lossy AAC audio, which is why a .m4a file can hold either kind and why the extension alone does not tell you which. The rarer .alac extension does exist, but many programs do not recognise it, and a file carrying it is often a .m4a in disguise that you may need to rename to .m4a before some players will open it. In short, seeing .m4a on an Apple Lossless file is entirely normal, and the way to be sure a given .m4a is lossless is to check its details rather than its name.
📦 Codec vs Container
Getting the idea of a codec and a container straight makes everything about ALAC clearer, so here is the distinction in plain terms.
A codec is the method that squeezes the audio down and later expands it again, and ALAC is one such method. A container is the file that wraps the encoded audio together with details like the track name and length, and for ALAC that container is the MP4 audio file ending in .m4a. So an ALAC file is really Apple Lossless audio placed inside an MP4 container. The same container can carry audio squeezed by a different codec, which is exactly why an .m4a might hold lossless ALAC in one case and lossy AAC in another. Keeping the two ideas apart, the codec that encodes and the container that holds, explains almost every question people have about this format.
An ALAC file, from the outside in
.m4a file (MP4 container) |- track title, length, artwork |- audio encoded with ALAC # the lossless part
⚖️ ALAC vs FLAC
The format ALAC is most often compared with is FLAC, and the comparison is a fair one, since both do the same job. The real difference is not sound but ecosystem.
FLAC, the Free Lossless Audio Codec, is an open format that has been widely supported for years, while ALAC is Apple's own lossless codec. Both are lossless, so a track stored in either sounds exactly the same, with no quality advantage on either side. Where they part company is support. ALAC plays smoothly across Apple devices and apps, whereas FLAC is understood by a broader spread of players, phones and streaming services, including Android, which does not handle ALAC on its own. Their file sizes are usually close, with small differences depending on the music. The practical rule is simple, that ALAC suits a library built around Apple gear, while FLAC is the safer pick for mixed devices, and converting between them loses nothing because both keep the full recording.
| Trait | ALAC | FLAC |
|---|---|---|
| Quality | ✓ Lossless | ✓ Lossless |
| Made by | Apple | Open source |
| Apple devices | ✓ Native | ~ Limited |
| Android and wide support | ~ Limited | ✓ Native |
| File size | Usually close, varies by track | |
🔀 ALAC vs AAC
Because ALAC and AAC share the same .m4a extension, they are easy to mix up, yet they are opposites in one key way. One keeps everything, the other trades detail for size.
AAC is a lossy codec, the standard one Apple uses for downloads and much of its streaming, and it makes files small by dropping sound the encoder judges you will not miss. ALAC is lossless and keeps every part of the recording, so its files are noticeably larger. Both sit in the same .m4a container, which is why the extension cannot tell them apart, and the reliable way to know which you have is to look at the file's codec details, where it will read either Apple Lossless for ALAC or AAC for the lossy kind. One thing worth knowing is that turning a lossy AAC file into ALAC brings no benefit, since the detail AAC removed is already gone, so you would only get a bigger file holding the same reduced sound. ALAC is worth choosing when the source itself is lossless, such as a CD or a FLAC file.
🔍 Is My .m4a ALAC or AAC?
Since both lossless ALAC and lossy AAC wear the same .m4a extension, the practical question is how to tell which one a given file actually holds. Happily there are several quick ways, and they all read the file's real details rather than its name.
The fastest check on a Mac is to select the file and press Command and I, then look at the Kind line, where Apple Lossless audio file means ALAC and AAC audio file means the lossy kind. In the Music app or iTunes you can right-click the track, choose Get Info and read the Kind field on the File tab. On any system the free VLC player shows the same thing under its codec information, and a small tool called MediaInfo spells out the codec in full. There is also a rough size rule that works surprisingly well, since a lossless file is far larger than a lossy one, so a song of a few minutes that runs to more than roughly fifteen megabytes is almost certainly ALAC rather than AAC.
Ways to check what a .m4a really holds
# macOS Finder select file, press Cmd+I, Kind: "Apple Lossless audio file" = ALAC # Music app or iTunes right-click, Get Info, File tab, read Kind # VLC, any system Tools, Codec Information, shows ALAC or AAC
📂 How to Open an ALAC File
Playing an ALAC file is easy across Apple devices and quite doable elsewhere, and the right choice depends on the system you are on.
The fastest way to check or play one with nothing to install is the Univik File Viewer, which plays the audio right in your browser. On Apple gear the file plays natively in the Music app on a Mac or iPhone and in QuickTime, since Apple Lossless is built in. On Windows the free VLC media player handles ALAC without any extra setup, and it works on every system, which makes it a reliable all-round choice. Windows Media Player can play these files too once a suitable codec pack is added. If a file uses the awkward .alac extension and a player refuses it, renaming it to .m4a usually does the trick, since the contents are the same.
Play in a browser
The Univik File Viewer opens an ALAC file instantly with nothing to install.
On Apple devices
The Music app and QuickTime play ALAC natively on a Mac, iPhone or iPad.
On Windows or Linux
VLC plays ALAC on any system, and it needs no extra codecs to do it.
🔄 How to Convert It
Converting an ALAC file is common, usually to play it on a device outside the Apple world or to save space, and it is straightforward to do.
A quick option is the Univik File Converter, which recodes ALAC to another format from your browser with no software needed. The most useful conversion is often to FLAC, the open lossless format, which keeps the sound perfect while working on Android and a wider range of players, so a lossless library stays lossless. When you need smaller files or the widest compatibility, converting to MP3 or AAC gives you that, though these are lossy, so some detail is dropped in exchange for size. Converting to WAV gives a raw, uncompressed copy for editing. A good habit is to keep the original ALAC file, since it holds the full recording and lets you convert again to whatever format you need later without losing quality twice.
🗂️ Where ALAC Is Used
ALAC shows up wherever Apple and high quality audio meet, and knowing the main places helps explain why you have run into one.
Its biggest home today is Apple Music, whose lossless tier delivers songs encoded with ALAC at qualities up to studio grade, available to subscribers at no extra cost. Before streaming took over, ALAC was the format many people chose in iTunes when ripping their CD collections, because it kept the discs at full quality while saving space, and those libraries are still around. Anyone building a careful digital archive of their music on Apple devices tends to reach for ALAC for the same reason. You also meet it when audio tools export an Apple friendly lossless file. In short, if you use Apple products and care about sound quality, ALAC is the format working quietly behind the scenes.
🏛️ A Short History
Apple introduced the Apple Lossless Audio Codec in 2004, adding it to iTunes and QuickTime so that people could store CD quality music without the large size of a raw recording.
For its first years ALAC was a proprietary Apple format, but in late 2011 Apple released it as open source and royalty free, which let other software and hardware support it freely and helped it spread beyond Apple's own products. The format gained fresh importance when Apple Music added a lossless streaming tier, putting ALAC at the centre of how the service delivers high quality sound. From a way to rip CDs to the engine behind lossless streaming, ALAC has stayed Apple's answer to keeping music at full fidelity, holding its own against the open FLAC format for well over a decade.
❓ Frequently Asked Questions
An ALAC file is audio saved with the Apple Lossless Audio Codec, Apple's way of compressing sound without losing any of it, so what you hear is an exact copy of the original recording in a smaller file. ALAC stands for Apple Lossless Audio Codec, and the key word is lossless, meaning nothing is discarded, unlike everyday formats such as MP3 that drop detail to save space. Because ALAC is a codec rather than a file type of its own, the audio is almost always kept inside a standard Apple audio file ending in .m4a, though you occasionally see the rarer .alac extension. Apple introduced it in 2004 for high quality music that still saved room.
This is normal and not a mistake. An extension usually names the container that holds the audio, not the codec used to encode it, and Apple Lossless audio is placed in the standard MP4 audio container whose files end in .m4a. The same .m4a container also carries lossy AAC audio, which is why the extension alone cannot tell you which kind a file holds. The rarer .alac extension does exist, but many programs do not recognise it, and such a file is often a .m4a in disguise that you may need to rename to .m4a before some players will open it. To be sure a .m4a is lossless, check its codec details rather than its name.
Both ALAC and FLAC are lossless codecs, so a track stored in either sounds exactly the same, with no quality difference. The real distinction is ecosystem. ALAC is Apple's format and plays natively across iPhones, iPads, Macs and Apple Music, while FLAC is an open format supported by a wider range of players, phones and services, including Android, which does not handle ALAC on its own. Their file sizes are usually close, varying a little with the music. So ALAC suits a library built around Apple devices, FLAC is the safer choice for mixed devices, and converting between the two loses nothing since both keep the full recording.
They serve different purposes, so neither is simply better. ALAC is lossless and keeps every part of the recording, giving the best possible quality at the cost of a larger file, while AAC is lossy and makes much smaller files by discarding sound the encoder judges you will not miss. Both share the .m4a extension, which is why they are easy to confuse, and you tell them apart by checking the file's codec details. For serious listening, archiving or good headphones, ALAC is the higher quality choice, whereas AAC suits streaming and saving space on a phone. Note that converting a lossy AAC file to ALAC brings no benefit, since the detail AAC removed is already gone.
On Apple devices an ALAC file plays natively in the Music app and QuickTime, since Apple Lossless is built in, so you can usually just double-click it. On Windows the free VLC media player plays ALAC with no extra setup, and because VLC works on every system it is a reliable all-round choice. Windows Media Player can play these files once a suitable codec pack is added. To check or play one without installing anything, a browser tool like the Univik File Viewer plays the audio with nothing to set up. If a file uses the .alac extension and a player refuses it, renaming it to .m4a usually works, since the contents are the same.
The easiest way is a browser tool like the Univik File Converter, which recodes an ALAC file into another format with nothing to install. For a lossless result that works beyond Apple devices, convert to FLAC, which keeps the sound perfect and plays on Android and a wide range of players. When you want smaller files or the broadest compatibility, convert to MP3 or AAC, though these are lossy and drop some detail in exchange for size. Converting to WAV gives an uncompressed copy for editing. It is worth keeping the original ALAC file, since it holds the full recording and lets you convert again later without losing quality twice.
In quality terms yes, because ALAC is lossless and keeps the entire recording, while MP3 is lossy and permanently removes parts of the sound to make smaller files. Played back, an ALAC file is identical to the original, whereas an MP3 is a reduced version, and on good headphones or a proper sound system the difference can be audible. That said, on cheap earphones or in a noisy setting many people cannot hear it, and MP3 files are much smaller, which is why they remain popular. For a quality music library, archiving or careful listening, ALAC is the better choice, while MP3 wins when small size and wide compatibility matter most.
Not out of the box, because Android does not support ALAC on its own the way Apple devices do. You have two practical choices. The first is to install a third-party music app that adds ALAC playback, several of which exist for Android. The second, and often the tidier option, is to convert your ALAC files to FLAC, the open lossless format that Android plays natively, which keeps the audio perfectly lossless while making it work everywhere on the device. Since ALAC and FLAC match in quality, converting between them loses nothing, so a FLAC copy on Android sounds identical to the ALAC original.
The Music app on a Mac, or iTunes on Windows, rips CDs to ALAC with a quick settings change. Before importing, open the import settings and set the format to the Apple Lossless Encoder rather than the default AAC, then insert the CD and import it. Each track is saved as a lossless .m4a that keeps the disc at full quality while taking up far less room than an uncompressed copy. This was for years the main reason people chose ALAC, since it let them archive a CD collection without losing a thing, and those libraries play natively across Apple devices. If you later need the tracks on non-Apple gear, converting them to FLAC keeps them lossless.
ALAC handles high-resolution audio comfortably, supporting depths up to 32-bit and very high sample rates, and Apple Music uses it for both its Lossless tier at CD quality and its Hi-Res Lossless tier up to 24-bit and 192 kHz. Dolby Atmos is a separate thing, though. Apple Music's Spatial Audio with Dolby Atmos is not delivered by ALAC but by a different, Atmos-specific stream, so a plain ALAC file is stereo or standard multi-channel lossless rather than an Atmos mix. In short, ALAC is the format behind Apple's lossless and Hi-Res lossless music, while Dolby Atmos spatial audio rides on its own separate technology.
Both give you the full original audio, but they get there differently. WAV stores sound uncompressed, keeping every sample as raw data, which makes the files large. ALAC keeps the same complete audio but compresses it losslessly, so an ALAC file is meaningfully smaller than the equivalent WAV while decoding back to exactly the same sound. ALAC also handles track details like title, artist and artwork neatly inside the file, whereas WAV has only basic support for that kind of information. So for editing or maximum compatibility with audio software, WAV has its place, but for storing a music library at full quality with proper track information and less wasted space, ALAC is usually the better choice.
It started proprietary but is now open. When Apple introduced ALAC in 2004 it was a closed, Apple-owned format, but in late 2011 Apple released it as open source and royalty-free, with the reference codec made freely available. That change let other software and hardware support ALAC without paying or reverse-engineering it, which is why you now find ALAC handled by many non-Apple players and tools. So while ALAC is still very much Apple's format and works best in the Apple world, it is no longer locked away, and its openness is part of why it spread as widely as it has.
Because they keep everything. A lossless ALAC file stores the complete recording with no detail removed, so it is naturally bigger than a lossy MP3 or AAC file that has thrown data away to shrink. That said, ALAC is far from uncompressed, since it squeezes the audio to roughly half the size of a raw WAV while staying perfectly lossless, so it is a middle ground between huge raw files and small lossy ones. If size is a concern, you can convert an ALAC file to a lossy format like MP3 or AAC for portable use and keep the ALAC original for quality, or move to a lower resolution if your copy is Hi-Res. The size is simply the price of keeping every part of the sound.
📝 Summary
An ALAC file is audio encoded with the Apple Lossless Audio Codec, Apple's way of compressing sound without discarding any of it, so decoding the file returns audio identical to the original recording in a smaller size. The key word is lossless, which sets ALAC apart from lossy formats like MP3 and AAC that permanently drop detail to save more space. A point that causes real confusion is that ALAC is a codec, a method of encoding, rather than a file type of its own, so the audio is almost always stored inside the standard MP4 audio container whose files end in .m4a, and only rarely in a file carrying the .alac extension. Because that same .m4a container also holds lossy AAC audio, the extension alone cannot tell you whether a file is lossless, and the reliable way to know is to check its codec details, which read Apple Lossless for ALAC. ALAC is most often compared with FLAC, the open lossless codec, and the two match in quality, differing only in support, since ALAC is native across Apple devices while FLAC works more widely including on Android. Apple introduced ALAC in 2004 and made it open source and royalty free in 2011, and it now powers the lossless tier of Apple Music at qualities up to studio grade, as well as the CD libraries many people ripped in iTunes. To play an ALAC file, Apple devices handle it natively through the Music app and QuickTime, VLC plays it on any system, and the Univik File Viewer opens it in a browser, while the Univik File Converter turns it into FLAC to stay lossless, or MP3 and AAC when small size matters more than keeping every detail.