Audio Compressor
Compress any audio file directly in your browser — fast, private, and free. Powered by the native Web Audio API with hardware acceleration. No uploads, no waiting, no external downloads.
Compression Result
FAQ
Is my audio uploaded to a server?
No. This tool uses your browser's native Web Audio API and MediaRecorder API to decode and re-encode audio entirely within your browser tab. Your file never leaves your device.
What is Bitrate and how does it affect quality?
Bitrate determines how much data is stored per second of audio. Higher bitrate = better audio quality + larger file. Lower bitrate = smaller file + possible quality reduction (e.g., loss of high frequencies). Common recommendations: 320 kbps for archival/music, 128–192 kbps for general music, 64–96 kbps for podcasts/voice, 32–48 kbps for voice-only (phone quality).
What is Sample Rate?
Sample rate is how many audio samples are captured per second. 44.1 kHz is CD quality and the most common for music. 48 kHz is used in video production. 22 kHz is sufficient for speech and podcasts. 8 kHz is telephone quality — very small files, voice only.
Should I use Mono or Stereo?
For music, podcasts with stereo production, or content where audio positioning matters, keep Stereo. For voice recordings, interviews, and simple podcasts, converting to Mono halves the audio data with minimal perceived quality loss — resulting in significantly smaller files.
What output formats are available?
Available formats depend on your browser. Chrome and Edge typically support WebM/Opus (excellent quality at low bitrates) and OGG/Opus. Safari supports MP4/AAC. The tool automatically shows only formats your browser can produce and remembers your selection.
Why is Opus better than MP3 at low bitrates?
Opus is a modern audio codec that significantly outperforms MP3 at low bitrates (below 128 kbps). At 64 kbps, Opus sounds noticeably better than MP3 at the same bitrate. It's the recommended format for compressed audio for web delivery.
Can I compress FLAC or WAV files?
Yes. FLAC and WAV are lossless formats that can be very large. This tool decodes them and re-encodes to a compressed lossy format (WebM/Opus or OGG), which can reduce file size by 70–90% with minimal perceptible quality loss at bitrates of 128 kbps or above.