Compress audio file
Shrink a song, podcast or voice note to a small Opus file that keeps good sound, using your browser’s built-in encoder. Your inputs stay in this browser tab.
Your result
A little input. A useful result.
Your result will appear here.How to use compress audio file
Shrink a song, podcast or voice note to a small Opus file that keeps good sound, using your browser’s built-in encoder. This free tool runs locally after you choose to start.
- Choose supported files from your device.
- Adjust quality, channels as needed.
- Choose the action button. Review the result, then copy text or download a file when available.
- Choose Clear all when finished to remove inputs and results from the interface.
Limits, without the small print.
Most MP3, WAV, M4A, AAC, OGG, Opus, WebM and FLAC files work, depending on your browser. Maximum 20 MB in total and about 5½ minutes of stereo or 11 minutes of mono. The result is an Opus audio file (.opus) that plays in current browsers and most media players; some older Apple devices may need another app. Your original files are not changed. Needs a browser with built-in audio encoding, such as a current Chrome, Edge or Firefox.
One job runs at a time. You can cancel it; jobs stop after 30 seconds. Browser and device capabilities affect performance.
Understand the safeguards →What this tool does
64 kbps keeps music sounding close to the original at about half a megabyte per minute. 32 kbps is clear for speech, podcasts and voice notes. Choose Mono for recordings made with one microphone.
Example input
Select a supported local file; the visible settings are a starting example.
What to expect
Review the generated local preview or downloadable copy before using it.
Questions people often ask.
Does compress audio file upload my data?
No. This tool processes your input inside your browser. Your text and files are not sent to an application server. The static host receives page and asset requests; see our privacy explanation.
Is this tool free for work and study?
Yes. No account, paid API, usage subscription or watermark fee is required. You remain responsible for your content rights and checking results. Hosting providers and their free tiers are separate from this open-source software.
What should I check before relying on the result?
Most MP3, WAV, M4A, AAC, OGG, Opus, WebM and FLAC files work, depending on your browser. Maximum 20 MB in total and about 5½ minutes of stereo or 11 minutes of mono. The result is an Opus audio file (.opus) that plays in current browsers and most media players; some older Apple devices may need another app. Your original files are not changed. Needs a browser with built-in audio encoding, such as a current Chrome, Edge or Firefox. Review important outputs against the source, especially financial, legal, identity, medical and research calculations.
Which audio files can I use?
Most MP3, WAV, M4A, AAC, OGG, Opus, WebM and FLAC files work, depending on your browser. If a file does not open, convert it to WAV or MP3 with another app first.
Why is the WAV result larger than my MP3?
WAV is uncompressed, so it keeps every sample. That makes it ideal for editing and compatibility, but larger. Choose Mono, or 16 kHz for speech, to make it smaller, or use Compress audio file for a small Opus file.
Is my recording uploaded anywhere?
No. Your browser decodes the audio, and a worker on your device cuts, joins and saves it. Nothing is sent to a server or kept after you close the page.