Compress audio in your browser
Drop an MP3, WAV, OGG, AAC, M4A or FLAC file. It stays in this tab, and we send you to the matching compressor.
or browse your device. Batches welcome, we detect the format
Pick a format, or drop a file and we will.
Each card is a live compressor. Same privacy model as the rest of the site: the file is processed in this tab and never sent anywhere.
Compress MP3
Pick a bitrate, or a size to land under. Speech in mono at 64 kbps is a fraction of the original and sounds the same on a phone.
Open the MP3 toolCompress WAV
WAV is raw PCM, so size is arithmetic: channels, sample rate and bit depth. This page writes 16-bit WAV and lets you cut the rest honestly.
Open the WAV toolCompress OGG
This writes Opus inside Ogg. Lower the bitrate, downmix speech, or hit a size target. Prefer MP3 only when old-player compatibility matters more.
Open the OGG toolCompress FLAC
FLAC has no honest bitrate or target-size dial. Savings come from an unused stereo channel or removable cover art and tags; otherwise the audio is already doing its job.
Open the FLAC toolCompress M4A
M4A is AAC audio inside MPEG-4, the combination used by Apple Music and iTunes. This page changes the soundtrack; it is not a video compression tool.
Open the M4A toolCompress AAC
AAC usually sounds better than MP3 at the same bitrate. This writes a plain ADTS .aac stream; choose MP3 instead only when old-player compatibility matters more.
Open the AAC toolHow to compress audio
Drop the audio
One track or several of the same kind. We read the container from its bytes, so an M4A named as MP3 still opens the M4A tool.
Land on the matching compressor
You pick a bitrate, optionally downmix to mono, and hear both versions before you save. Video is out of scope on purpose: that belongs on vidshift.io.
Listen and save
If the smaller file sounds fine, download it. If it does not, raise the bitrate and run it again. Nothing left your machine.
The home page routes any file we can compress, including code, fonts and ZIP archives.
Same in-browser, nothing-uploaded approach, built specifically for video.
Which audio format, and what bitrate?
Audio splits cleanly into lossy and lossless, and the split decides everything else. MP3, AAC, M4A and OGG are lossy: they discard sound you are unlikely to hear and are measured in bitrate, so the size of the file is essentially the bitrate multiplied by the duration. FLAC and WAV are lossless, storing every sample exactly, which is why an album as WAV runs to hundreds of megabytes. WAV is not even compressed: its size is pure arithmetic, channels times sample rate times bit depth.
Bitrate is the dial that matters, and the honest guidance depends entirely on the content. Speech is forgiving: a lecture, interview or podcast in mono at 64 kbps is close to indistinguishable from the original on a phone or laptop, and mono alone halves a stereo recording of one person talking. Music is not: 128 kbps is audibly thin on anything with cymbals or reverb, 192 is comfortable, and past 256 you are mostly buying reassurance.
A lossless file cannot be made smaller by pretending it is lossy, which is why the FLAC page has no bitrate slider. What it can do is drop channels you are not using and strip tags and cover art, and an embedded album cover is often a megabyte on its own. If you genuinely want a FLAC to become small, what you want is to convert it to a lossy format, and that is a different operation with a real cost attached.
Questions
How do I compress audio without uploading it?
Drop the file on this page. It is decoded in your browser and routed to the MP3, WAV, OGG, AAC, M4A or FLAC tool. There is no upload, so a private recording stays private.
Which audio formats can I compress?
MP3, WAV, OGG, AAC, M4A and FLAC are live. Video files are sent to vidshift.io rather than being half-handled here.
Will compressing audio change how it sounds?
Lowering the bitrate always discards some detail. The tools play the original and the result side by side so you can hear the trade before you keep it. Speech often survives a much lower rate than music.
Can I compress audio to a target size?
Yes on the formats that search for a bitrate. You name a figure, the tool walks the rungs, and it tells you where it landed or why it could not get there.
What bitrate should I use for a podcast or a voice recording?
Mono at 64 kbps, and check it before you commit. Speech has a narrow frequency range and one speaker needs no stereo image at all, so downmixing halves the file before the bitrate does anything. An hour of talk lands around 28MB at that setting and sounds the same as the original through phone speakers or earbuds. Music needs far more: 192 kbps is comfortable, and below 128 you will hear it on cymbals and reverb.
Why will my FLAC not compress much?
Because FLAC is already lossless compression, and there is no quality left to trade away. The FLAC tool has no bitrate slider for that reason: a control that appeared to shrink a lossless file would be lying about what it was doing. What it can do is drop unused channels and strip tags and embedded artwork, and a cover image is often a megabyte by itself. If you want a genuinely small file, convert to a lossy format instead and accept the trade knowingly.
Does compressing audio remove the tags and the cover art?
With the switch on, which is the default, yes: the ID3 or Vorbis tags go, and so does the embedded cover art, which on a short track is often most of the file. The result panel says what it dropped. Turn the switch off and the tags are carried into the new file.
Is this audio compressor free?
Yes. Encoding runs on your own CPU, so there is no per-minute charge, no account and no watermark.