Convert audio
Turn a WAV into MP3, an M4A into WAV or a folder of recordings into FLAC: pick the format, the bitrate, the sample rate and the channels, and convert up to 50 files at once. Everything runs in your browser.
Updated October 30, 2026
Options
Edit title, artist, album
Empty fields keep the source's own; the cover art is kept. Applies to every file in the list.
How it works
- Drop your audio files (or a folder) anywhere on this page.
- Pick the format, or a preset for voice, music or archiving.
- Download each file, or all of them as a ZIP.
The jobs it does most
A WhatsApp voice note, an Opus or OGG file, into an MP3 that any player and any office computer opens. An iPhone voice memo, M4A, into MP3 or WAV for an editor. A WAV from a recorder into MP3 before mailing it. A folder of MP3 rips into FLAC for the archive, or the other way round for a car stereo. Drop the files, pick the format, and the estimate under the options shows about how big each result will be.
Settings that make the difference
The presets set everything at once: Voice gives MP3 at 64 kbit/s in mono at 22 kHz, small and clear for speech; Music gives MP3 at 256 kbit/s; Archive gives FLAC. Bitrate runs up to 320 kbit/s for MP3 and AAC. Mono halves the size of a recording that was stereo for no reason, such as a phone call. Bit depth matters only for WAV and FLAC: 16-bit is CD quality, 24-bit for a studio file you will edit again.
Batches and privacy
Up to 50 files, or a whole folder, convert one after the other and come back as a ZIP, each up to 2 GB. A video dropped in the list gives its sound track. Every file is decoded and encoded in a worker inside your browser; nothing is uploaded, and the typed tags stay on this device.
Why people use it
Free, no account
Every tool is free, with no sign-up, no e-mail address and no limit on how often you use it.
Your files stay on your device
The browser opens the file and processes it in memory, on your device. Nothing is uploaded, so nothing can be kept, leaked or looked at.
No watermark
The result is yours as it is: no watermark, no branding, no trial version.
Any device
A phone, a tablet or a computer with a current browser is enough: no app to install, no software to update.
Works offline after the first visit
The browser keeps the pages and their engines, so a tool you have opened once keeps working without a connection.
Open-source engines
The code that does the work is open-source software, named on the Licences page, running as WebAssembly in your browser.
Why it is private
Everything you type or drop here is handled by your browser, on your device. Nothing is uploaded. To verify, open your browser's developer tools, go to the Network tab, and use the tool: you will see no request carrying your data.
While a file is being processed, the counter under the result shows the page's network traffic: 0 requests and 0 B for your data.
How to check it yourself, step by step
What you can check yourself
Open your browser's developer tools on the Network tab before you drop a file: while the tool works you will see no request carrying your data, and the counter under every result shows the page's own measurement.
The site sets no cookies, so there is no cookie banner. Anonymous usage counts and error reports without file names are the only things that leave the page, as the privacy policy describes.
Every change goes through thousands of automated tests in three browser engines, including a guard that fails a test if a single byte of a file leaves the page.
Frequently asked questions
- Which formats can I convert?
- In: MP3, WAV, M4A (AAC), OGG (Vorbis or Opus), Opus, FLAC, and the sound of MP4, MOV, WebM or MKV videos. Out: MP3, WAV, M4A, Opus, OGG and FLAC. MP3 is written with LAME, loaded as a separate file only when you pick it; WAV by our own code; AAC, Opus and FLAC by your browser's encoders. Firefox cannot write M4A, and a browser without a FLAC encoder gives you a WAV instead, just as lossless, with a note.
- Why does my OGG file contain Opus?
- No browser can encode Vorbis, the codec OGG files used to carry. An .ogg from this tool holds Opus, which plays in every current browser, on Android and in VLC; some older players and car stereos expect Vorbis, so choose MP3 for those.
- Which bitrate and sample rate should I pick?
- 'Automatic' keeps the source's bitrate when the codec stays the same, otherwise 192 kbit/s for MP3 and AAC and 128 for Opus. For speech, 64 kbit/s mono is plenty; for music, 192 to 256. Keep the source's sample rate unless an app asks for another: 16 kHz for speech recognition, 44.1 kHz for CDs, 48 kHz for video.
- Is converting lossless?
- WAV and FLAC keep every sample. MP3, AAC and Opus are lossy, and turning one lossy file into another loses a little more each time, so convert from the original when you can. When a file already is in the format you picked and nothing else changes, you get it back as it is, untouched.
- Are titles and cover art kept? Can I change them?
- In MP3, M4A, OGG, Opus and FLAC, yes, unless you choose to remove them. Open 'Edit title, artist, album' to type new ones: what you type replaces the source's, the cover art stays, and it applies to every file in the list. Typed tags are remembered on this device only and never put in the page address. WAV files made here carry no tags; the result says so.
- Is anything uploaded?
- No. Every file is decoded and encoded in a Web Worker in your browser, one after the other, and the network meter under the results shows 0 B.
- Can I convert a WhatsApp voice note to MP3?
- Yes. The .opus or .ogg file a chat app saves is read as it is; choose MP3 and the Voice preset for a small file that plays everywhere.
- Can I convert an iPhone voice memo (M4A) to MP3?
- Yes. Drop the M4A, choose MP3 and download. For a file you want to edit, choose WAV instead.
- Does it work on a phone?
- Yes, in the browser, with nothing to install. A few songs at a time are fine; a very long file may exceed a phone's memory, and the tool says so before it starts.
- Can I make an MP3 smaller?
- Yes: choose MP3 with a lower bitrate, or mono for speech. It is encoded again, so a little quality is lost each time; convert from the best copy you have.
Install it as an app
Chrome, Edge and Android browsers offer to install this site from the address bar or the menu; on iPhone use Share, then Add to Home Screen. It opens like an app, keeps working offline and still processes everything on your device.