Convert from
- WAV
- FLAC
- AIFF
- Apple Lossless (ALAC)
Recommended output
- MP3
- AAC
- Opus
Compress Audio
Downmix large WAV, FLAC and AIFF files to compact MP3, AAC or Opus at the bitrate you choose.
About this converter
WAV and AIFF store every sample uncompressed, while FLAC and ALAC shrink the same samples without losing any. These are the formats of recordings, masters and music rips, and because all four are lossless, any smaller result is a deliberate trade of detail for size.
This tool accepts those four inputs and writes MP3, AAC or Opus. Each output is a lossy codec, so the bitrate, sample rate and channel count you choose decide how much of the original survives.
How it works
Choose an output format
Pick the format you want the result in before you add anything. Every file in the queue is converted to that one format, so the choice shapes the whole run.
Add your files
Drop files onto the page or use the file picker. Each file is checked against the formats this tool accepts, and anything that does not match is reported by name.
Download the result
When a conversion finishes, download the converted file. Uploads and results are deleted after 2 hours, so keep your own copy.
Formats you can convert
Every file below is accepted as input, and the result is written as MP3, AAC, and Opus. All three outputs are lossy, so a higher bitrate keeps more of the original; the sample rate and channel count can also be reduced.
- WAV — uncompressed PCM, the format of recordings and editing exports
- FLAC — lossless compression that keeps every sample at a smaller size
- AIFF — Apple's uncompressed PCM container, the Mac counterpart of WAV
- Apple Lossless (ALAC) — Apple's lossless codec, usually stored inside an M4A file
Quality and what changes
A lossless source cannot become lossy without losing something. MP3, AAC and Opus discard what listeners are least likely to hear, and a modern codec reaches the same perceived quality at a lower bitrate than an old MP3. The bitrate slider sets the budget, a lower sample rate discards the highest frequencies, and folding stereo to mono removes a channel. Normalizing loudness and keeping tags are separate switches.
Privacy and limits
Guests can convert files up to 100 megabytes and run 5 conversions per day. A free account raises the limit to 500 megabytes and 25 conversions per day, and paid plans go up to 100 gigabytes.
Files you upload and the results you download are kept only long enough for you to collect them and are deleted after 2 hours. After that window nothing of yours remains on the server.
You do not need an account to convert a file; signing in only raises the size and daily limits.
Questions and answers
Which output should I choose?
Opus is the most efficient of the three and a good default. AAC is widely supported by phones and Apple software, and MP3 plays almost everywhere. Choose the one your player or device requires.
Do I lose audio quality?
Yes. All three outputs are lossy, and every source here is lossless, so the encoder is discarding audio detail. A higher bitrate keeps more of it, but nothing beats converting only when you need the smaller file.
Can I change the sample rate or channels?
Yes. The sample rate can drop to a lower value and the channels can fold to mono; leaving either on source keeps the original. Lowering them reduces the data the encoder has to carry.
How long are my audio files kept?
Uploads and results are deleted after 2 hours. Download each result when its conversion finishes, and nothing is kept after that window.