How to convert FLAC to ALAC without losing quality
FLAC and ALAC are both lossless audio codecs, which means a direct conversion can preserve the music exactly at the sample level. The decoder reads the FLAC, reconstructs its PCM values, and the ALAC encoder writes those same values into the new file. Amplitude, dynamics, noise, channel layout, sample rate and bit depth can all remain unchanged, provided the converter does not resample, dither or normalise the signal.
For many Australian listeners, the appeal of ALAC is compatibility rather than a sonic upgrade. iPhone, iPad and Mac users can use Apple Lossless in the .m4a container, while Android and Windows users may still prefer AAC. Independent artists and small labels in Melbourne, Brisbane, Adelaide and Perth often keep FLAC masters for review, archiving or delivery before preparing lossy files for streaming. Having both formats gives those teams a practical way to support different release pipelines.
Conversion cannot restore detail that was lost before the FLAC was created. A FLAC made from a lossy master may sound clean, but its samples contain only the information left by the earlier lossy stage. The reliable goal is therefore a bit-perfect transcode: no sample-rate conversion, no reduction in bit depth, no dithering and no automatic gain changes. Tags, artwork and folder organisation also need attention because the containers do not store metadata in exactly the same way.
Australian buyers will encounter local tools priced in Australian dollars, usually with 10% GST included, so open-source converters are often the first option to compare. The National Film and Sound Archive of Australia in Canberra demonstrates why preservation-grade audio matters. At the same time, personal conversion of recordings you own is distinct from distributing commercial music without permission. ACMA requirements apply to legitimate music services; changing a local file does not grant additional copyright rights or improve an Apple Music stream.
Why FLAC-to-ALAC conversion remains lossless
FLAC usually stores audio in its own .flac container, whereas ALAC is commonly carried in an MPEG-4 file with an .m4a extension. Apple Lossless is the name of the codec, not the file extension. A converter can read a tagged FLAC and produce a playable M4A without altering the soundtrack. Keeping the original extension and source format remains important, though, because renaming a file to .m4a does not convert or repair anything.
Bit-perfect describes the decoded signal, not equality between the two finished files. FLAC and ALAC use different compression methods, so their byte sizes and checksums will differ even when every decoded sample matches. The meaningful test is whether the source and destination have the same sample rate, bit depth, channel count and sequence of PCM values. Tag or artwork differences should be recorded separately and never mistaken for an audio failure.
Conversion is worth doing when an Apple-oriented catalogue, device or editing setup benefits from M4A, or when a shared release workflow requires both codecs. It is unnecessary when existing players already handle FLAC reliably. It also does not create a lossless version of music received through a lossy streaming service. Apple Music’s catalogue quality is controlled by the service; importing a local ALAC file cannot turn that catalogue download into a higher-tier stream.
Prepare files before changing format
Begin by inspecting the source rather than trusting its filename. Confirm whether it is genuinely FLAC, then note the sample rate, bit depth, channel count and duration. A media-information panel in a trusted player can show most of these values, while ffprobe -v error -show_streams input.flac provides a fuller report. Pay particular attention to 24-bit and high-resolution files, because a converter that silently outputs 16-bit PCM has changed the signal even if its settings say lossless.
Create a working copy and keep the FLAC original read-only. Checksums and the original metadata make it easier to prove that the source remained untouched, especially across a large archive. A separate system-level backup is sensible for Windows users; the EaseUS backup guide explains one route to a lifetime licence for Todo Backup 8.7 before batch work begins. That backup should supplement, rather than replace, the untouched source file.
Decide where the M4A files will live before conversion. Use filenames that make the format and version obvious, and retain a simple mapping between each source and output so albums are not duplicated under conflicting names. If artwork or lyrics matter, test them separately because audio equivalence does not guarantee that they survived. Australian buyers comparing commercial utilities should check quoted AUD prices, GST treatment and update policies before downloading an unfamiliar installer.
Run the conversion with trusted tools
FFmpeg is a dependable command-line choice because it exposes the relevant settings directly. Obtain it from its official distribution or a reputable package repository, then use:
ffmpeg -i input.flac -map 0:a:0 -c:a alac -map_metadata 0 output.m4a
The audio stream is mapped explicitly, encoded as ALAC and placed in an M4A container. Basic title, artist, album and track tags are copied, while unusual metadata may require a separate export. This direct route also avoids wasting storage on an unnecessary WAV intermediate.
For a graphical workflow, choose a converter that explicitly supports FLAC input, Apple Lossless output and M4A containers. In a Windows tool such as Lossless Audio Converter, add the FLAC files, select ALAC as the output codec, verify the original sample rate and bit depth, choose an output folder and start a small batch. On macOS, FFmpeg can be run in Terminal or through a maintained graphical front end. The critical action is checking the encoder panel after adding each source.
Leave sample-rate and channel settings at their source values unless there is a deliberate reason to change them. Avoid options labelled dither, normalise, replay-gain adjustment, fade processing or smart volume levelling. These features may appear convenient, yet they alter sample values. If the source is 16-bit, confirm a 16-bit ALAC result; for a 24-bit source, confirm that the selected encoder and container support 24-bit output. A converter offering only 16-bit ALAC cannot perform a 24-bit-preserving job.
Once the settings are correct, convert one representative track and listen before processing a collection. Check the beginning, a quiet passage and a dense instrumental at normal volume. Do not rely on a louder output as proof of quality, since gain changes can mask a down-conversion. Keep the converter’s log or displayed output report, and do not delete the source until the ALAC file has passed the sample-level checks.
Compare the practical conversion options
Most practical choices fall into command-line, graphical batch converter, power-user player and editing-suite groups. The right option depends less on a claimed bit rate than on whether the software preserves the source sample format and avoids hidden processing.
| Option | Workflow | Audio control | Best suited to |
|---|---|---|---|
| FFmpeg | Command line | Explicit codec, sample format and stream mapping | Technical users and scripted batches |
| Lossless Audio Converter | Windows graphical interface | Clear output settings and batch handling | Windows users wanting visual checks |
| foobar2000 with an encoder | Plugin-driven player and converter | Precise tagging, though components need careful setup | Power users managing diverse formats |
| Digital audio workstation export | Editing-project workflow | Convenient for edited audio, but effects may be included | Users who must edit before final export |
FLAC and ALAC are both efficient lossless formats, but their compressed sizes are not identical. Depending on the material and encoder, ALAC may be slightly larger or smaller than FLAC, so conversion should not be chosen on the promise of guaranteed space savings. If the purpose is portability to Apple devices, file size can still be a tie-breaker after quality and metadata have been checked.
A reliable verification and backup checklist
Use a short excerpt to test the complete selected workflow before committing to a full archive. This exposes unsupported bit depths, tag problems and accidental normalisation while the cost of correction is small. It also gives a clean reference for checking whether the output really contains the source samples.
- Preserve the FLAC original, its metadata and a checksum before conversion.
- Match the source sample rate, bit depth and channels while disabling resampling, dithering and normalisation.
- Compare decoded PCM or a waveform difference rather than the compressed-file checksum.
- Confirm tags, artwork and duration manually, including tracks with silence or long embedded images.
- Test a short file before batching, then retain the logs and output reports.
An audio editor can perform a sample-accurate visual comparison of the FLAC and decoded ALAC. With FFmpeg, decoded framemd5 or PCM checksums can also be compared after forcing both files into the same sample format. Do not compare the original container’s checksum with the M4A’s checksum; different metadata and compression rules guarantee different results. If differences appear, inspect encoder settings, channel mapping and whether the player normalised either file.
Keep at least two copies in separate locations. One can stay on the working drive while another is synced to a reviewed cloud or network storage service, but large archives are often better uploaded over a fixed connection than a metered mobile plan. This matters for regional Australia using fixed wireless or slower NBN services, as well as metropolitan users with data limits. A second physical drive at home or work provides protection against account or hardware failure.
Start with one representative FLAC track, create an ALAC copy using FFmpeg or a trusted graphical converter, and verify the decoded samples before processing the full collection. Keep the original FLAC master and the finished M4A files in separate backup locations so the new format adds compatibility without putting your audio at risk.