Audio converter
Turn any sound file into MP3, WAV, FLAC, M4A or OGG. Your files are converted on this device and never uploaded.
- Nothing is uploaded
- Works offline after first use
- Open source
- No watermark · limit is your device’s memory; phones hold less
Converts audio between MP3, WAV, FLAC, M4A and OGG, or pulls the sound out of a video, for one file or a batch. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory, and phones hold less; give the page a short while after your first run to save itself for offline use, and then it works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
How it works
- Drop one or more sound files (MP3, WAV, FLAC, M4A, OGG, Opus, AIFF) or videos, or tap to pick them.
- Choose the format to convert to. For MP3, M4A and OGG pick a quality; WAV and FLAC keep every sample.
- Convert. One file downloads straight away; several download as a zip.
In your browser, not on a server
Your browser decodes the sound with the decoders it uses to play media on any website. The new file is written in your tab: MP3 by LAME compiled to WebAssembly, WAV by a few lines of code, FLAC by a small lossless encoder in this site’s code (fixed predictors and Rice coding, as the FLAC format describes), and M4A or OGG by the browser’s own AAC and Opus encoders (WebCodecs), packed by Mediabunny (MPL-2.0). WAV and FLAC keep the original sample rate.
Compared with upload-based tools: Online audio converters upload every file, queue it, cap free use at a few files or a few hundred megabytes, and keep the upload for hours. Recordings of meetings, unreleased songs and voice memos are private. Here the files never leave your device and a whole folder converts at once.
Verify it yourself. Give the page a short while after your first run to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Are my files uploaded?
No. Your browser decodes the sound with its own decoders, and the new file is written inside the page: MP3 by LAME compiled to WebAssembly, WAV and FLAC by small encoders in this site’s code, M4A and OGG by the browser’s built-in AAC and Opus encoders. Your files are not uploaded, so the size limit is your device’s memory (phones hold less), and the page works offline after one visit and a short wait (MP3 output needs one MP3 run first).
Which format should I choose?
MP3 plays on everything. M4A (AAC) sounds a little better than MP3 at the same size and is what iPhones and Apple Music use. OGG with Opus is the smallest for a given quality and suits websites, games and voice. WAV is uncompressed, for editing. FLAC keeps exactly the same sound as WAV at about half the size, for archiving music.
Is WAV to FLAC really lossless?
Yes, for 16-bit audio. The FLAC decodes to the same samples, at the same sample rate, as the 16-bit WAV this tool would write. 24-bit recordings are stored as 16-bit, which is still beyond what anyone can hear, but keep the original if you need 24-bit for mastering.
Why can’t my browser make an M4A?
M4A needs an AAC encoder, and browsers only have one where the operating system provides it: Safari, and Chrome or Edge on Windows and Mac have it, while Firefox and Chrome on Linux do not. The page tells you when you pick M4A. MP3 plays in all the same places.
Does converting improve the quality?
No. Converting can keep the quality (to WAV or FLAC) or lower it (to MP3, M4A or OGG), never raise it. An MP3 turned into a FLAC is a bigger file with the same MP3 sound. If a recording sounds thin or quiet at the source, check the microphone with the mic test before you record it again.
More video and audio tools
Screen recorder
Capture your screen, one window or a tab, with its sound and your voice. The video is made in this tab and never uploaded.
Voice recorder
A voice memo, a voice-over or a quick demo, recorded in this tab and saved as MP3. The sound never leaves your device.
Volume booster
Boost a quiet recording, turn down a loud one, or even out a batch. Done on this device, never uploaded.
Remove background noise
Keep the voice, lose the hiss, hum and fan noise. Cleaned on this device, never uploaded.
Popular conversions
Guides
- How to convert WAV to MP3WAV files are large; MP3 is the smaller, more compatible format most people actually need. Here is how to convert between them.
- How to merge audio filesJoining voice notes, podcast segments or songs end to end is simple once you know the right tool. Here is the desktop way and a private browser way.
- How to reduce MP3 sizeAn MP3 gets smaller when you lower its bitrate, make it mono, shorten it, or switch format. Here is what each saves, with measured results.
- A free CloudConvert alternative for everyday filesCloudConvert measures its free tier in credits tied to conversion time, not files, which makes it hard to predict when you will hit the limit. Here is an alternative with nothing to meter.
- A free Convertio alternative with no file size capConvertio's free plan caps both file size and how many conversions you get per day. Here is an alternative with no such ceiling.