Compress Audio

Shrink audio file size by lowering the bitrate or converting to a more efficient codec, in your browser. Private voice notes and family recordings stay on your device.

Conversions

About Compress Audio

Compress Audio reduces the size of MP3, WAV, M4A, AAC, FLAC, Ogg, and other common audio files by lowering the bitrate, downsampling, or converting to a more efficient codec. Choose a target (128 kbps for voice, 192 kbps for music, or a higher level for archival). The conversion runs entirely in your browser with FFmpeg compiled to WebAssembly, so interview recordings, dictations, and private voice memos never leave your device — important for journalists, lawyers, and healthcare workers handling sensitive audio.

Best for

  • Shrinking a multi-hour interview recording for chat or email share
  • Reducing voice memos to fit a 25 MB attachment cap before transcription
  • Compressing podcast episodes for fast upload to a hosting service

Pros

  • +Pick target bitrate (96, 128, 192 kbps) for the right size/quality trade
  • +Switch codecs (MP3, AAC, Opus) for further size savings
  • +FFmpeg in WebAssembly runs locally — sensitive audio never uploaded

Cons

  • −Lossy compression below 96 kbps shows audible artifacts in music
  • −Compressing already-low-bitrate audio produces double-generation loss

How to use Compress Audio

  1. 1

    Select or upload the source files from your local device storage.

  2. 2

    Specify conversion settings, options, or target output formats.

  3. 3

    Wait for the client-side browser logic to process the files securely.

  4. 4

    Download the finalized outputs directly to your system.

Frequently Asked Questions

Which bitrate should I pick?
For speech (podcasts, interviews, voice memos) 96–128 kbps MP3 or 64 kbps AAC usually sounds clean. For music pick 192 kbps MP3 or higher; below 128 kbps music shows audible splash and cymbal artifacts.
Can compressing convert to a smaller codec?
Yes. Switching WAV → MP3 or FLAC → Opus is the most size-efficient. Opus gives the best voice quality per byte; MP3 still wins for universal player compatibility; AAC is the modern middle ground.
Will compressing reduce the dynamic range of music?
Lossy compression does not compress dynamics by design, but at very low bitrates the encoder simplifies quiet/loud detail to save space. Keep high bitrate for classical or jazz with wide dynamic range.
Can I compress lossless FLAC files?
Yes — FLAC files are common in music archives and convert well to MP3 or Opus. Lossless input has full quality to start, so the lossy output sounds closest to the original at the chosen bitrate.
Are my private audio files uploaded during compression?
Never. FFmpeg runs as a WebAssembly binary in your browser. Interview tapes, dictations, and sensitive voice memos stay on your device the whole time.

Related tools

FREE

100% Free

No hidden fees, no subscriptions, and no limits. Enjoy complete access to all features gratis.

SIGNUP

No Signup Required

Start converting immediately without creating an account or sharing email address.

PRIVACY

Private & Secure

Your files never leave your device. All processing is completed locally for maximum privacy.

BATCH

Batch Conversion

Convert multiple files simultaneously to save time. Fast and efficient multi-file queue.

LOCAL

Runs in Browser

Utilizes advanced client-side WebAssembly technology to process files directly inside your tab.

FORMATS

200+ Formats

Supports a wide variety of formats including images, documents, audio, video, and more.

USER REVIEWS

Compress Audio Quality Rating

4.8
25 reviews

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