Audio Converter
Convert audio to MP3, WAV, M4A or Opus in your browser. Runs in your browser.
About this audio converter
This audio converter turns MP3, WAV, M4A, AAC, OGG, Opus and FLAC files into MP3, WAV, M4A or Opus, right in your browser. Use it when a file won't play in your car, won't upload to a form, or is simply too big.
Nothing is uploaded. Your browser decodes each file and encodes the new one on your own computer, so there is no file size cap, no daily quota and no waiting in a server queue.
Pick the bitrate, sample rate and channels, edit the tags, and convert a whole folder at once.
Features
Common inputs, video included
MP3, WAV, M4A, AAC, FLAC, OGG Vorbis, Opus and WebM audio all open, and so does the soundtrack of an MP4, MOV or MKV video.
Four outputs that really work
MP3 and WAV in every browser. M4A (AAC) and Opus where your browser has an encoder for them. Anything it can't make is greyed out with the reason.
Bitrate, sample rate and channels
MP3 from 64 to 320 kbps, AAC up to 256 kbps, Opus from 32 kbps. Keep the original sample rate or pick one, and keep, merge to mono or force stereo.
WAV in 16, 24 or 32-bit
16-bit is CD quality and what most apps expect. 24-bit and 32-bit float suit audio editors and leave headroom for further processing.
Tags you can edit
Title, artist, album, year, genre, track number and comment are read from each source file and can be changed per file. Cover art is carried into MP3 and M4A.
Batch with ZIP
Add as many files as you like. They convert one after another so memory stays low, with progress and an estimated time left. Download each file or one ZIP.
How to use the audio converter
- 1Add one or more audio files, or try the demo file already in the list.
- 2Choose MP3, WAV, M4A or Opus with the bitrate, sample rate and channels you want.
- 3Press Convert, check the preview, then download each file or all of them as a ZIP.
When to use it
WhatsApp and Telegram voice notes
Voice notes arrive as Opus audio in an .ogg or .opus file, which many players and editors refuse. Convert them to MP3 at 64 or 96 kbps and they play anywhere. To get the words out, transcribe the recording next.
FLAC music for a car or an old player
Many car stereos and older MP3 players don't read FLAC. Convert to MP3 at 256 or 320 kbps and keep the tags so the track names still show on the display.
WAV for an audio or video editor
Editors handle WAV fastest and without decoding surprises. Convert compressed files to 24-bit WAV at the project's sample rate, usually 48 kHz for video.
Files too big to send
A 10-minute WAV voice recording is about 100 MB. As a mono 64 kbps MP3 it is under 5 MB, small enough for most email limits. If you're sending pictures too, compress the photos the same way.
Does converting to MP3 lose quality?
Yes, a little. MP3, AAC and Opus are lossy formats: they throw away detail the encoder thinks you won't hear. At 192 kbps and above most people can't tell an MP3 from the CD in a blind test. At 128 kbps careful listeners start to notice on cymbals and applause.
Going the other way can't help. Converting an MP3 to WAV gives you a much bigger file with exactly the same sound, because the detail is already gone. Keep your FLAC or WAV originals and make MP3 copies from them.
Which bitrate and format should I pick?
File size depends on bitrate and length, not on the source. Each minute at 128 kbps takes about 0.94 MB, at 192 kbps about 1.4 MB, and at 320 kbps about 2.3 MB. Uncompressed 16-bit stereo WAV at 44.1 kHz takes about 10 MB per minute.
- Music for any device: MP3 at 192 to 320 kbps.
- Speech, lectures, podcasts: MP3 at 64 to 128 kbps in mono, or Opus at 32 to 48 kbps.
- Apple devices and video projects: M4A (AAC) at 128 to 256 kbps.
- Editing and archiving: WAV, 24-bit if the source was a high-resolution recording.
What sample rate should I use?
44,100 Hz is the CD standard and 48,000 Hz is the video standard. Both capture sound up to about 22 kHz, which is above the roughly 20 kHz limit of human hearing. Keep the original rate unless a program asks for a specific one.
Some formats fix the rate for you. Opus always works at 48 kHz, AAC here uses 44.1 or 48 kHz, and MP3 rates below 32 kHz are limited to 160 kbps by the MP3 standard.
Mono or stereo for voice recordings?
Mono. A single voice has no useful stereo information, and a mono WAV is half the size of a stereo one. With MP3 the gotcha is that size depends only on bitrate, so a mono file at 128 kbps is the same size as a stereo one but spends all its bits on one channel and sounds cleaner. Drop the bitrate to 64 kbps if you want the smaller file.
Why use Mavros
| Mavros | Typical upload sites | |
|---|---|---|
| Upload required | No, conversion runs on your device | Yes, files sit on a server for hours |
| File size and daily limits | None, beyond your device's memory | Size caps and a few free conversions per day |
| Edit tags per file | Yes, read from the source first | One set of tags, or none |
| Preview before download | Yes, a player on every result | Usually download only |
| Batch download | ZIP of every converted file | Often a paid feature |
| Formats listed | Only ones your browser can really encode | Long lists done server-side |
Tips
- Press Convert again after changing a setting. Only the files marked “Settings changed” are redone.
- Need only part of a track? Cut the section you want before converting, so you encode less.
- Got the audio inside a video? Drop the video straight in, or use the dedicated video to MP3 tool.
- Recording something new? The voice recorder saves MP3 or WAV directly.
Questions
Are my audio files uploaded?
No. Decoding and encoding run inside your browser, and your files never leave your device. The only download is the 133 KB MP3 encoder, fetched from this site the first time you make an MP3.
Can I convert FLAC to MP3?
Yes. Add the FLAC files, pick MP3 and a bitrate, and convert. 320 kbps keeps as much quality as MP3 can, and the title, artist and album tags are copied across.
Why can't I convert to FLAC?
Browsers don't include a FLAC encoder that web pages can use, so FLAC is accepted as input only. Choose WAV when you need a lossless copy. It is larger than FLAC but plays in more places.
Why are M4A or Opus greyed out?
Your browser has no encoder for that format. Firefox can't make AAC, for example, and some browsers can't make Opus. Chrome and Edge on Windows or macOS handle both, and MP3 and WAV work everywhere.
What is the best bitrate for MP3?
192 kbps is the usual sweet spot for music, and 320 kbps is the maximum. For speech, 64 to 128 kbps is enough. Choosing a higher bitrate than the source file had only makes the file bigger.
Can I convert many files at once?
Yes. Add a whole batch, press Convert, and they are processed one after another. When they finish, download them one by one or all together in a ZIP file.
Are tags and album art kept?
Yes, with Write tags on. Tags are copied from each source and you can edit them per file. MP3 and M4A also keep the cover picture, while WAV and Opus keep the text tags only.