Sample M4A audio files for testing — free, CC0, hotlinkable

M4A is AAC audio in an MP4 container, the file Apple devices produce and many streaming services deliver. Unlike a bare ADTS stream, the container carries an index of the audio, so players can seek and show a duration before reading the whole file.

m4a/aac-30s.m4a is a 440 Hz sine wave, thirty seconds long, 48 kHz stereo AAC at 128 kbps. The same kind of tone appears across the audio formats here, which makes it easy to compare how one pipeline handles several containers and codecs.

Use it to test audio players and seeking, metadata readers, transcoders, and upload forms that accept M4A. It also checks MIME handling: the file is served as audio/mp4, and code that expects audio/x-m4a, or looks only at the extension, may reject it. Related formats: AAC for the same codec without a container, and MP3.

curl -O https://loremfile.dev/m4a/aac-30s.m4a

<audio src="https://loremfile.dev/m4a/aac-30s.m4a" controls></audio>