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.
Compress audio in three steps
A free audio compressor that runs entirely in your browser. Drop files, pick a bitrate, download smaller audio.
- 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.
- 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.
- 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 the audio compressor free?
Yes. No account, no email, no limits — compression runs on your own device, so there is nothing for us to meter.
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 quality. Compress from the original file when you can, and don't re-compress below the bitrate 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.
Need the words, not just the audio?
SlayScribe turns any audio or video into accurate text in seconds — transcripts, captions, and subtitles in 99 languages.
Transcribe to text