Converters Audio converter
Convert between MP3, M4A, WAV, AAC, OGG and FLAC in batches, with the bitrate under your control.
192 kbps is transparent for music. 128 is plenty for speech.
Drag files here, or
Converted to MP3 on your device. The converter itself is a 9.8 MB download, once.
Ready. Runs locally on your device.
Your files stay on your device. The tool works directly in your browser, using your device to process your files. Nothing is sent to our servers, and we never receive, store, or see your files or figures.
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Cite this page
Reembun. (2026, August 12). Audio converter. https://reembun.com/audio-converter
How to use it
Add your audio files
Drop in as many as you like. They are decoded and re-encoded in this tab, so nothing is uploaded.
Let the converter load once
The engine downloads on the first run and stays cached afterwards, which is why the second conversion starts straight away.
Choose the format
MP3 plays everywhere, M4A and AAC are smaller at the same quality, WAV is uncompressed for editing, FLAC is lossless but compressed, OGG is the open option.
Set the bitrate
192 kbps is transparent for music and 128 kbps is plenty for speech. Higher only makes the file bigger once the source has nothing more to give.
Download
A single file downloads on its own, a batch is packaged as a ZIP.
The formats, honestly compared
| Format | Compression | Typical size, 4 minutes | Best for |
|---|---|---|---|
| MP3 | Lossy | 4-9 MB | Anything that must play everywhere |
| M4A (AAC) | Lossy | 4-9 MB | Apple devices; better sound per byte than MP3 |
| WAV | None | 42 MB | Editing, mastering, transcription tools |
| FLAC | Lossless | 20-25 MB | Archiving without giving up a single sample |
| OGG Vorbis | Lossy | 4-8 MB | Games and open projects avoiding patents |
| AAC | Lossy | 4-9 MB | Streaming pipelines that want a raw stream |
MP3 is thirty years old, technically beaten by everything newer, and still the right answer more often than not, because it is the only format that genuinely plays on every device ever made.
M4A holds AAC and sounds noticeably better than MP3 below about 128 kbps. Above that the gap closes. It is what iTunes, Apple Music and every iPhone recording produces.
WAV stores raw samples with no compression at all. Ten times the size of an MP3 and no better to listen to, but it is what audio editors, DAWs and most transcription services expect to be handed.
FLAC compresses losslessly: about half the size of WAV, every sample recoverable exactly. The right archive format, and useless for compatibility.
Lossy to lossy loses twice
MP3, M4A, AAC and OGG all work by throwing away sound the ear is unlikely to notice. Each format makes different decisions about what to discard.
Converting between them decodes the first set of discards and then applies a second, different set on top. The result is worse than either conversion would have been from the original master, and worse again every time you repeat it.
Two rules follow:
- Convert from the best copy you have. If a lossless original exists, use it.
- Do not round-trip. MP3 to WAV and back to MP3 does not restore anything. It loses a second generation.
Converting to WAV or FLAC never loses anything, but it also never recovers anything. A WAV made from a 128 kbps MP3 is a large file that sounds exactly like a 128 kbps MP3.
Choosing a bitrate
- 320 kbps - music you intend to keep, and anything headed for decent headphones.
- 256 kbps - close enough to 320 that few can tell, for 20% less.
- 192 kbps - the default. Transparent on most material for most listeners.
- 128 kbps - speech, podcasts, lectures. Half the size with no audible cost on a voice.
- 96 kbps - a voice note that has to fit in an email.
Doubling the bitrate does not double the quality. The gains flatten sharply above 192, which is why a 320 kbps file is not audibly twice as good as a 160 kbps one.
Nothing is uploaded
Audio is often more sensitive than the video it came from: consultations, interviews, legal dictation, therapy sessions, voice notes. This tool runs FFmpeg inside your browser tab, so the file is read from your disk and written back to it, with no server in between and nothing to take on trust.
Common questions
Which formats can it read?
Anything FFmpeg can decode, which is effectively everything you will meet: MP3, M4A, AAC, WAV, FLAC, OGG, Opus, WMA, AIFF, AMR, and the audio inside any video file. The output list is deliberately shorter, covering the six formats people actually ask for.
Does converting between MP3 and M4A lose quality?
Yes, in both directions. Both are lossy, so converting one to the other decodes one set of discarded detail and applies a different set on top. At 192 kbps and above it is inaudible to almost everyone, but it is real, and it compounds if you keep converting the same file back and forth.
What bitrate should I use?
192 kbps is the sensible default and is transparent to most listeners on most material. Use 320 for music you are keeping, 128 for speech and podcasts, and 96 for a voice recording you need to email. WAV and FLAC ignore the setting because neither discards anything.
Can I convert several files at once?
Yes. Drop in as many as you like and they are converted one after another, then offered as a single ZIP. The engine loads once and is reused for the whole batch, so a folder of 40 tracks costs one engine download rather than 40.
Is my audio uploaded anywhere?
No. The conversion runs inside your browser tab using a copy of FFmpeg your browser downloads once. Voice memos, interview recordings and dictation never leave your device.
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