Audio Compressor
Compress audio files by adjusting bitrate and channel count directly in your browser. Reduce file size for podcasts or music while keeping your data private.
MP3, WAV, M4A, AAC, OGG, FLAC, Opus · up to 1 GB
Tips
- The browser downloads a 30 MB processing engine once on initial use, allowing subsequent compression to work entirely offline.
- Selecting 64 kbps mono is sufficient for voice recordings and reduces the file size to roughly one-fifth of its original volume.
- Avoid dropping below 128 kbps for music tracks to prevent high frequencies and cymbals from sounding muffled or distorted.
How to use it
- 1 Select or drag your audio file into the tool.
- 2 Choose your desired target bitrate and select mono downmixing if compressing voice recordings.
- 3 Start the compression process and save the resulting audio file to your device.
What you should know
Audio compression reduces file size by discarding acoustic data that human hearing perceives less distinctly, known as perceptual audio coding. Uncompressed formats like WAV preserve every sample but consume significant storage and bandwidth, often exceeding ten megabytes per minute. Converting to compressed formats like MP3 or AAC using controlled bitrates drastically shrinks file footprints. A 320 kbps bitrate maintains near-transparent fidelity for complex musical arrangements, whereas voice notes and spoken podcasts retain clear intelligibility even at 64 kbps. Lowering the bitrate directly decreases the output file size in exact mathematical proportion to audio duration.
This tool re-encodes your audio files inside your browser using a WebAssembly engine, eliminating server uploads completely. You can configure target bitrates and downmix stereo channels into mono to maximize compression efficiency on spoken audio. The trade-off for smaller sizes is the irreversible removal of high-frequency harmonics and spatial stereo separation when downmixing. Non-standard audio metadata tags and embedded album art might be stripped during re-encoding to keep the output stream clean. Because the engine operates single-threaded inside your active tab, processing long audio files requires active browser focus until encoding completes.
Frequently asked questions
Will compressing audio make it sound noticeably worse?
It depends on the bitrate and content type. Voice recordings remain clear at 64 kbps, while music generally requires at least 128 kbps to avoid noticeable distortion in treble and percussion.
Are my audio files uploaded to a remote server?
No, all decoding and compression happen locally within your web browser using WebAssembly. Your files never leave your device.
Why does compression take longer for large audio files?
The in-browser engine runs on a single CPU thread inside the browser tab. Re-encoding long recordings requires processing every audio sample sequentially, which takes time proportional to the total audio length.
Guides
Articles and format references related to this tool.
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