Audio Converter
HeavyConvert audio between formats, change sample rate and channels.
Input
Settings
Run
Results
Results will appear here once you run the tool.
About Audio Converter
Convert audio between formats, change sample rate and channels. Drop one or more files into Audio Converter — it handles up to 100 at a time.
Your files stay on your device. ZyncTools has no upload step: the file is read in your browser, processed there, and handed straight back to you. There is no account, no watermark and no size cap beyond what your own device can hold.
Settings. Audio Converter gives you control over output format, mp3 bitrate, channels, sample rate and normalise the volume.
This one works your device hard. Processing happens locally, so a large file takes real time and real CPU. It is still faster than uploading for most files, and nothing leaves your machine.
Also known as: audio, convert, mp3, wav, m4a, ogg, flac.
How to use Audio Converter
- Add your input. Drop your files onto the upload area, or click to browse. You can add up to 100 at once, and they are read in your browser rather than uploaded.
- Choose your settings. Adjust output format, mp3 bitrate, channels and the other 2 settings to suit what you need.
- Run the tool. Press Run. Processing happens on your own device, so the time it takes depends on your machine rather than a queue.
- Save the result. Copy the output, or press Download to save it. Nothing is kept once you close the tab.
Frequently asked questions
Are my files uploaded when I use Audio Converter?
No. Audio Converter runs entirely inside your browser. Your file is read locally, processed on your own device, and handed straight back to you. You can confirm this yourself: open your browser's developer tools, watch the Network tab, and run the tool — no request carries your data anywhere.
Is Audio Converter free?
Yes, completely. No account, no sign-up, no watermark on your output, and no cap on how many times you can use it. The project is open source under the AGPL licence.
Is there a file size limit?
There is no server limit, because nothing is uploaded. The practical ceiling is your device's memory — on a modern laptop, files up to a few hundred megabytes are comfortable, while phones handle less. If a tab becomes unresponsive, the file was too large for the memory available.
Can I process several files at once with Audio Converter?
Yes — up to 100 at a time. When there are more than a few results they are packaged into a ZIP so you get everything in one download.
Why does this take a while?
The work happens on your device rather than a server, so speed depends on your own processor. That is the trade for never uploading anything. Larger files and higher quality settings take proportionally longer.
Does Audio Converter work offline?
Mostly. The site caches itself after your first visit, so it keeps working without a connection. Tools that need a specialised library — PDF editing, OCR, QR codes, MP3 encoding — need a connection the first time you run them, then that library is cached too.