Audio Compressor

Shrink audio files by up to 90% — right in your browser, with the size saved shown per file.
No installs, no watermarks, 100% free.

Drop your files here to upload
Video or audio — MP4, MOV, MKV, WAV, M4A…

Stop replaying it — read it instead.

Compress audio in three steps

A free audio compressor that runs entirely in your browser. Drop files, pick a bitrate, download smaller audio.

  1. Step 1

    Upload your files

    Drag audio (or video — the audio track is extracted) into the upload area. WAV, MP3, M4A, FLAC, OGG and more all work, in batches.

  2. Step 2

    Pick a bitrate

    64–96 kbps is plenty for speech and voice notes; 128 kbps keeps music decent. Every file shows how many percent smaller it came out.

  3. Step 3

    Download compressed audio

    Save files one by one or grab everything as a Zip. Compression happens on your device — nothing is uploaded.

When to compress audio

Smaller files send faster, store cheaper, and still sound fine for their job.

Send by messenger & email

Voice memos and recordings that exceed attachment limits shrink to a fraction of their size at 64–96 kbps.

WAV & FLAC recordings

Lossless studio files are huge by design. Compress a 500 MB WAV to a ~30 MB MP3 for sharing and drafts.

Podcasts & interviews

Speech doesn't need 320 kbps. Mono-friendly bitrates cut hosting and download size without hurting clarity.

Free up storage

Batch-compress old recordings and archives — the Zip download makes round-tripping a folder painless.

See the savings

Each file shows "−N% smaller" when it's done, so you can pick the bitrate that hits your size target.

Need the words instead?

If the goal is meeting notes, not a smaller file — SlayScribe turns the recording into accurate text.

How audio compression works

Bitrate is the size dial: it's how many kilobits describe each second of sound. Re-encoding at a lower bitrate keeps what your ear cares about and drops the rest — 64 kbps speech is perfectly intelligible at roughly a tenth of a WAV's size. Everything runs locally in your browser, so your recordings stay private.

Frequently asked questions

Is it free?

Yes. No account, no email, no limits — the compressor runs entirely in your browser.

How much smaller will my file get?

Depends on the source: WAV/FLAC shrink by 80–95%; a 320 kbps MP3 re-encoded at 96 kbps shrinks by ~70%. The exact saving is shown per file.

Which bitrate should I pick?

64–96 kbps for speech (voice notes, meetings, podcasts), 128 kbps for casual music. Lower bitrate = smaller file, gradually softer highs.

Does compressing again lose quality?

Each lossy re-encode loses a little. Compress from the original when you can, and don't re-compress below what you need.

Do my files get uploaded?

No — compression happens on your own device from start to finish.

Can I compress the audio out of a video?

Yes — drop a video and the audio track is extracted and compressed. For video files themselves, a dedicated video compressor is coming.

More converters

Audio ConverterWAV to MP3FLAC to MP3Video & Audio to MP3

Need the words, not just the audio?

SlayScribe turns any audio or video into accurate text in seconds — transcripts, captions, and subtitles in 98+ languages.