WEBM to M4A Converter

AUTO-DELETE/Files are processed on our server and deleted as soon as conversion finishes.

or drop your images here

How to Convert WebM to M4A Online

WEBM to M4A: what changes in the file

This tool takes a WEBM file, processes it with FFmpeg on DownloadVideo.vn servers and returns a M4A file.

The picture track of the WEBM is dropped; only the audio is kept and packaged as M4A.

Both WEBM and M4A are lossy, so converting adds another generation of compression: a small further loss that is usually hard to notice after one conversion.

How WEBM and M4A differ

Property	WEBM	M4A
Full name	WebM	MPEG-4 Audio (AAC in an MP4 container)
Introduced	Google, 2010	Apple / MPEG, 2003
Compression	lossy	lossy
Common codecs	VP8, VP9, AV1, Vorbis, Opus	—
Strengths	royalty-free, built for HTML5 video; small files at good quality	standard for iTunes, iPhone ringtones and voice memos; keeps tags and cover art
Limitations	many editors, iPhones and older TVs handle it poorly; VP9/AV1 encoding is slow	some older car stereos and Windows apps do not recognise the extension

Measured with a sample file

On September 25, 2026 we ran the tool on our production server with a sample file: a 10-second 1280×720 video (VP9 + Opus), 1.2 MB.

Result: 1.2 MB → 159 KB, processed in 1.6 s. Output: AAC audio at 48 kHz stereo, 128 kbps.

Real sizes depend on your content (how complex the picture and sound are, and the length); the figures only show the order of change.

Before you convert

The tool always re-encodes the picture and sound, even when the source codec would already fit the target format.
Up to 500 MB per file; a conversion that runs longer than 10 minutes is cancelled.
The file is sent to our server for conversion and deleted as soon as processing ends, including when it fails.

Frequently asked questions

Is the picture from the WEBM kept in the M4A?

No. M4A is an audio format, so only the sound is kept.

Does converting WEBM to M4A reduce quality?

Slightly: it is a second round of lossy compression. One conversion is usually hard to notice, but repeated conversions add up.

How does the file size change from WEBM to M4A?

With our sample file: 1.2 MB → 159 KB. Your file may differ depending on its content.