Sample M4A Files — Download AAC Test Audio (Apple / iTunes Format)
MPEG-4 Audio (AAC in MP4 container) · .m4a · MIME type audio/mp4
Download a sample M4A file — AAC audio in an MP4 container, the format iPhone Voice Memos, iTunes purchases and most Apple-ecosystem apps produce. If your product accepts audio uploads, M4A is probably the second most common thing you will receive after MP3.
Because it is an MP4 file, M4A supports fast seeking, embedded artwork and rich metadata. Every browser plays it; the samples here are AAC-LC stereo at 128 and 192 kbps.
Download sample M4A files
| File | Details | Size | Download |
|---|---|---|---|
sample-audio-15s-128kbps.m4a | 15 s · AAC · 131 kbps · 44.1 kHz · stereo | 246 KB | |
sample-audio-60s-192kbps.m4a | 1 min · AAC · 194 kbps · 44.1 kHz · stereo | 1.5 MB |
Need one of every audio format? Download the audio sample pack (1.7 MB, one small file of every audio format (9 files)).
Use these files from the command line or CI
Every URL is stable and CORS-open. Pin the SHA-256 in your test and you will know the moment a fixture changes.
# Download one file curl -O https://pnb-website-bucket.s3.us-east-2.amazonaws.com/samples/audio/m4a/sample-audio-15s-128kbps.m4a # Verify it (SHA-256 is listed for every file above) shasum -a 256 sample-audio-15s-128kbps.m4a # Machine-readable index of every sample file curl https://pnb-website-bucket.s3.us-east-2.amazonaws.com/samples/index.json | jq '.files[] | select(.format=="m4a")'
M4A format at a glance
| Full name | MPEG-4 Audio (AAC in MP4 container) |
|---|---|
| Extensions | .m4a |
| MIME type | audio/mp4 |
| Container | MP4 (ISO base media), 'M4A ' brand |
| Codec | AAC-LC (ALAC also possible in M4A) |
| Bitrates here | 128 kbps and 192 kbps |
| Magic bytes | … 66 74 79 70 4D 34 41 20 ("ftypM4A ") at offset 4 |
What people test with sample M4A files
- iPhone voice-memo uploads
- Transcribing or converting Apple-ecosystem audio
- MIME detection (audio/mp4 vs audio/x-m4a)
Frequently asked questions
Can I rename .m4a to .mp4?
It will usually open, since the container is identical, but audio-only MP4s are conventionally .m4a so players and apps know there is no video track. Keep the extension and set the MIME type to audio/mp4.
Are these M4A files safe to download?
Yes. Every file is generated by our own open script from scratch — nothing is scraped or user-uploaded — and contains no scripts, macros or executables. The SHA-256 of each file is published on this page so you can verify what you received.
Can I use the sample M4A files commercially?
Yes. They are free for any purpose, including commercial products, test suites, demos and redistribution, with no attribution required. There is nothing to license and no one to ask.
Can I hotlink these files or use them in CI?
Yes. Every link is a stable direct URL over HTTPS with Access-Control-Allow-Origin: * and long cache headers, so curl, wget, fetch() and test runners can pull them directly. A JSON index of every file is linked from each page (see the command-line section).
Related sample files
Testing a file pipeline? We build them.
Uploads, conversions, previews, document processing and media workflows are the kind of production systems Pine & Birch designs and runs for clients — which is why we needed these files in the first place.
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