What happens when you convert M4A to WebM
- Both formats are lossy. Re-encoding loses a little quality, so pick a bitrate at least as high as the original's.
- Opus works at 48 kHz, so audio is resampled to 48 kHz if needed.
- Mono and stereo are kept (or choose either); surround sound is mixed down to stereo.
- Tags such as title, artist and cover art aren't copied yet.
M4A vs WebM
| Feature | M4A | WebM |
|---|---|---|
| Compression | Lossy | Lossy |
| Size per minute | 1.2 MB | 1 MB |
| Plays on | Most devices and apps | Browsers, Android, VLC |
| Best for | iPhone, iTunes, Apple Music | Websites |
How to convert M4A to WebM
- Drop your M4A files on the box above, or click it to choose files. You can add many at once.
- Adjust the options if you want. The defaults work well for most files.
- Click Download for each WebM file, or "Download all" to get a ZIP.
Frequently asked questions
Is it safe to convert my files here?
Yes. Conversion happens entirely in your browser. Your files are never uploaded to a server, so nobody else can see them.
Is it free? Are there limits?
It's completely free, with no sign-up, watermarks or daily limits. The only limit is your device's memory for very large files.
Can I convert many M4A files at once?
Yes. Drop as many files as you like; they're converted one after another and you can download them all as a ZIP.
Will converting M4A to WebM reduce quality?
WebM removes sounds most people can't hear to make the file smaller. At the default bitrate most listeners won't notice a difference; pick a higher bitrate to be safe.
Which bitrate should I choose?
For music, 192 kbps MP3 or 160 kbps AAC sounds near-identical to the original, and Opus sounds great at 128 kbps. For speech and podcasts, 64–96 kbps is plenty.
Are tags and cover art kept?
Not yet. The sound is converted, but title, artist and album art aren't copied.