AMR → AIFF

No, and it is worth being blunt: nothing can. The AMR already discarded detail during its original encode, and wrapping what remains in a lossless AIFF preserves exactly that — no more. The file gets several times larger and sounds identical. It is still the right move before editing, because AIFF will not add a second generation of artefacts when you export. AIFF is the studio interchange format on macOS, handles metadata better than plain WAV, and imports into Logic and Pro Tools instantly. AMR destroys music: its 8 kHz bandwidth removes everything above telephone frequencies, and no amount of re-encoding brings it back.

Yes, and it is a genuine gain over AMR, which has nowhere dependable to store any of it. AIFF carries title, artist, album, year, track number and embedded cover art in the container itself, so a music library files it correctly without a manual pass.

Often not. AMR is decoded by essentially everything, including car head units and elderly players; AIFF needs software that knows the codec, which standalone hardware frequently does not have. If the destination is a car stereo or a portable player, that is a strong argument for staying on AMR. AIFF is as large as WAV with worse support outside the Apple world, so it is a poor choice for distribution.

Because one side of it is a speech codec rather than a music codec. It models the human vocal tract and discards everything outside telephone bandwidth, which is fine for a voice memo and destructive for anything with instruments in it. Converting away from it cannot restore the missing frequencies — they were never encoded in the first place.

If AMR is lossy and AIFF is lossless (e.g. MP3 → WAV), the AIFF is no better than the AMR — you cannot recover information already discarded. If AMR is lossless and AIFF is lossy, the AIFF codec recompresses; at 192 kbps the result is transparent for most content.

Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.

By default yes — 48 kHz AMR stays 48 kHz in AIFF. If you need to downsample for compatibility (96 kHz → 44.1 kHz for CD burning), the sample-rate option applies high-quality resampling in the same encode pass.

Not in this step. The converter has no loudness setting and leaves the level as it is. To even out the volume, run the finished AIFF through a Normalize tool on this site.

MP3 plays almost everywhere. AAC plays on Apple devices, most Android phones and Sonos. FLAC plays on Sonos and Android but not on older iPods, and WAV plays on nearly everything but makes large files. There are no device presets on this page, so choose the target format your player supports.