m4a.net
File format domains are a small but reliable category, because the search intent is unambiguous and visitors arrive with a task already in mind.
M4A is on hundreds of millions of devices without most owners thinking about it. It’s the container Apple uses for audio, the format voice memos save as, and the standard output of a great deal of consumer recording.
That gives this three-character .net a built-in audience. An audio conversion tool, a transcription service, a podcast platform, a file utility, or a media handling API would all be found by people who already know the letters.
There’s a second reading in policy circles where M4A is shorthand for a health coverage proposal, which broadens the buyer pool considerably for anyone in that space.
The .net is natural for a utility or service rather than a brand, and it keeps three characters affordable.
Offers welcome.