WebM to AAC Converter

What happens when you convert WebM to AAC

• AAC holds sound only, so the picture is discarded and the soundtrack is encoded as AAC at 192 kbps in an ADTS stream.
• If the WebM has several audio tracks, the first one is used.

How to convert WebM to AAC online

1. Press "Choose WebM files" and select one or more files, or drag them onto the box. You can add files of any size your device can hold in memory.
2. Adjust the settings if you need to: the bitrate controls quality and size. The defaults suit most people.
3. Press "Convert to AAC". The first audio or video conversion downloads the converter engine, about 32 MB, which your browser then keeps for next time.
4. Save each AAC with its download button. Close the tab and every trace of the files is gone from memory.

Why convert WebM to AAC?

WebM files usually come from web video, screen recorders and browser-based recordings. People convert them to AAC because raw AAC streams are what some broadcasters, podcast tools and hardware players ask for.

In short, WebM is good at what it was made for, and AAC is the more practical choice when the file has to play on another device or app. WebM plays in Chrome, Firefox and Edge, and in Safari since version 14.1, while AAC plays in all current browsers and on Apple and Android devices.

How to convert WebM to AAC on Windows, Mac, iPhone and Android

On Windows

Open this page in Chrome, Edge or Firefox, drag your WebM files in from File Explorer, and press Convert. Each AAC is saved to your Downloads folder. If you prefer a desktop program, VLC can also convert WebM to AAC: choose Media, then Convert / Save.

On a Mac

Safari, Chrome and Firefox all work. Drag the WebM files from Finder onto the drop zone and the AAC files land in Downloads.

On iPhone and iPad

Open the page in Safari and tap Choose WebM files. You can pick from Photos or from the Files app. The converted AAC appears in Files, in the Downloads folder.

On Android

Open the page in Chrome, tap Choose WebM files and pick them from Files or your gallery. The AAC is saved to the Download folder, where any file manager can find it. Keep the screen on while a long video converts, because Android may pause a tab in the background.

Best settings for WebM to AAC

AAC is a lossy format, so the bitrate decides both the sound quality and the file size. Size grows in a straight line with bitrate: double the bitrate and the file doubles.

The WebM was already compressed, so pick a bitrate at least as high as the original. Going higher does not add quality back, it only makes the file bigger.

WebM vs AAC: the differences

About WebM and AAC files

What is a WebM file?

WebM is a royalty-free subset of Matroska made for the web. Browser screen recorders and many online meeting tools save to WebM, which iMovie and many editors cannot import.

What is an AAC file?

AAC was designed as the successor to MP3 and sounds better at the same bitrate, especially below 128 kbps. A bare .aac file is a raw stream with no chapters or cover art; the same audio in a container is usually called M4A.

WebM to AAC not working? Common problems

• The conversion is slow. Audio and container changes take seconds, but re-encoding video runs on your own processor. Lower the resolution to 720p, close other tabs, and keep the device plugged in.
• The tab stops or reloads on a very large file. Browsers limit how much memory one tab can use, around 2 GB and less on phones. Split long recordings or convert them on a computer.
• Song titles are missing. Tags such as title and artist are copied when AAC can store them, but cover art is not carried over.

Convert WebM to AAC with ffmpeg

This converter runs ffmpeg inside your browser. If you would rather use the ffmpeg command line on your own computer, this command produces an equivalent AAC with the same kind of settings:

ffmpeg -i input.webm -vn -c:a aac -b:a 192k -f adts output.aac

Replace input.webm with the name of your file. For a whole folder of WebM files, run the command in a loop, or drop them all on the converter above, which processes them one after another.