Use this M4A to AIFF converter when an editor, project, or recipient requests an AIFF audio file. Upload one .m4a, start conversion, and download the AIFF when it finishes. The tool is free, with no account or software installation required.
The output is uncompressed 16-bit PCM AIFF. Your M4A may contain lossy AAC or lossless ALAC. Converting it does not restore AAC's discarded detail, and the fixed 16-bit output cannot preserve the full precision of a 24-bit ALAC source.
M4A input and AIFF output: what is different?
M4A names a file format, not one fixed codec. Apple's audio-format reference lists AAC and ALAC for M4A and integer PCM for AIFF. The source codec matters when deciding what the conversion can preserve.
| Property | M4A input | This tool's AIFF output |
|---|---|---|
| Extension | .m4a | .aiff |
| Audio encoding | May be AAC or ALAC | Signed 16-bit big-endian PCM (pcm_s16be) |
| Compression | Lossy for AAC; lossless for ALAC | Uncompressed PCM |
| Precision | Depends on the source codec and audio | Fixed 16-bit integer samples |
| Page display | Input preview depends on browser support | File card with download |
| Additional information | May include tags and artwork | Complete transfer is not guaranteed |
This page accepts .m4a files. Renaming an .mp4 or .m4b does not change its contents or guarantee that it meets this page's upload and decoding requirements. A valid extension alone does not establish that the file contains readable audio.
When converting M4A to AIFF helps
Import a recording into an editor that requests AIFF
An editor or project may specify uncompressed AIFF. Convert a copy and verify its duration, channel count, and channel layout after import. If the editor already reads your M4A correctly, an intermediate conversion may be unnecessary.
Meet a 16-bit AIFF delivery requirement
Check the recipient's specification before converting. This tool supplies 16-bit PCM AIFF, but it does not meet a requirement for 24-bit or floating-point output. Confirm sample rate and channels separately; the .aiff extension alone does not prove compliance with every delivery condition.
Prepare an audio asset for further work
You can make a PCM copy of a recording, sound effect, or individual musical passage for a compatible project. Keep the M4A as well if its source information or precision matters. For loops or synchronized material, test the start, end, and transition in the destination project rather than assuming identical timing.
How to convert M4A to AIFF online
- Upload one M4A. Select or drag in a complete
.m4afile up to 200MB and 30 minutes. Wait for the export or download to finish before uploading it. - Start conversion. Wait for the upload to finish, then start the task. AIFF is already selected, and the tool creates a fixed 16-bit PCM file.
- Download and check. Use the download on the completed file card, then open the AIFF in a compatible editor or player. The result area does not provide an inline AIFF player.
Each task processes one file. There is no batch upload, webpage-link conversion, or project import. Export the individual audio file first; the tool does not choose chapters or automatically divide a longer recording into clips.
Can M4A to AIFF be lossless?
For an AAC source, the AIFF stores decoded audio, but it cannot reconstruct information discarded during AAC encoding. Uncompressed output does not prove that the recording came from a lossless original. Keep that source distinction when organizing your files.
For a compatible 16-bit ALAC source, audio samples can be preserved if the sample rate, channels, and sample values remain unchanged. Changing the container or PCM byte order does not by itself reduce precision. This does not mean that the complete M4A and AIFF files, tags, or other metadata are identical.
The output is always 16-bit PCM. A 24-bit ALAC source cannot retain its full numerical precision in this output. This page does not offer 24-bit, floating-point, dither, sample-rate, or channel controls. Preserve the higher-precision original if later work needs it.
Compare at a similar volume and check the downloaded properties. Listening and matching metadata alone do not prove sample-for-sample preservation; an exact check compares decoded audio. Conversion does not remove noise, repair clipping, or restore missing sound.
Why the AIFF can be much larger
AAC and ALAC both store compressed audio, while this AIFF stores PCM without compression. The file will often grow, particularly from AAC, but there is no universal multiplier. Source content, duration, channels, and precision affect the comparison; reducing higher-bit-depth ALAC to 16 bits can also reduce the amount of PCM data to be stored.
For two minutes of 44.1kHz, 16-bit PCM, stereo audio contains 21.168MB, or about 21.17MB, of sample data. Mono contains 10.584MB, or about 10.58MB. The formula is 16-bit PCM audio data size (MB) = sample rate (Hz) × channel count × 2 × duration (seconds) ÷ 1,000,000. Each 16-bit sample occupies 2 bytes per channel.
These are decimal-MB calculations excluding headers and metadata, not measured conversion results or selectable settings. Files with the same PCM parameters and duration contain the same amount of sample data even when their overall file sizes differ because of structure and metadata.
The 200MB limit applies to the upload, and an AIFF output can exceed it. Duration is a separate limit: a small compressed M4A can still be longer than 30 minutes. Check both input limits and any delivery-size limit on the downloaded result.
If uploading, conversion, or playback causes trouble
M4A input reading depends on the browser and the audio inside the file. If the page cannot read its duration, try a compatible browser or check the source in the application that created it. In particular, an .m4a extension does not guarantee that a browser can read every ALAC recording.
If conversion fails, confirm that the file is complete and contains a supported audio track. Export a suitable copy from the original application if possible. The converter does not repair damaged recordings or make an unsupported file readable by changing its name.
A completed file card without a player is expected for AIFF. Download it and listen in a compatible application, then check duration, channels, and any loop or synchronization requirements. Inspect tags, artwork, and other source information separately; successful audio conversion does not guarantee that all of them remain usable.
Frequently asked questions
Is this M4A to AIFF converter free?
Yes. No account or credits are required. Each task processes one M4A file up to 200MB and 30 minutes. Batch upload, chapter selection, and automatic splitting are not available.
Does every M4A contain AAC audio?
No. M4A can contain AAC or ALAC, among other possible variations. AAC is lossy; ALAC is lossless. Check the actual source codec when assessing precision or file-size changes. This page does not guarantee every M4A variant is compatible.
Will conversion preserve the audio without loss?
A compatible 16-bit ALAC source can preserve its decoded samples if sample rate, channels, and sample values remain unchanged. AAC's previous losses cannot be recovered, and 24-bit ALAC cannot retain full precision in this fixed 16-bit output. Matching audio does not guarantee identical file bytes or metadata.
Can I get 24-bit or floating-point AIFF?
No. Output is fixed to uncompressed, signed 16-bit big-endian PCM AIFF (pcm_s16be). There are no higher-bit-depth, floating-point, dither, sample-rate, or channel settings. Keep the higher-precision M4A if you need those properties.
Why does the completed AIFF show a file card instead of a player?
That is the expected result display. The page provides a download without requiring the browser to play AIFF. Download the file and check it in a compatible editor or player; the absence of an inline player does not mean conversion failed.
Will tags, artwork, and editing information transfer?
Complete preservation is not guaranteed. Check the result in the intended application and keep the M4A if you need those details. The tool creates one audio file; it does not migrate a project or choose individual chapters.
What if the M4A cannot be uploaded or converted?
If a duration-reading error blocks upload, check the original file and try a compatible browser. Conversion needs a complete, readable audio track within the size and duration limits. A correct .m4a extension alone does not guarantee browser or service compatibility.