Free online AAC to XML converter

What the AAC format is

AAC (Advanced Audio Coding) is a lossy audio codec used for music, podcasts, video soundtracks, streaming, and mobile playback. Raw AAC files commonly use the .aac extension and ADTS framing; AAC audio is also frequently stored inside MPEG-4 containers such as .m4a and .mp4.

Apple Music and QuickTime, iTunes, VLC, FFmpeg-based applications, media recorders, smartphones, and many video editors can create or use AAC. An AAC file contains compressed audio frames and may contain limited stream information, but it is not a document format designed for general-purpose metadata exchange.

What the XML format is

XML (Extensible Markup Language) stores hierarchical, text-based data using elements and attributes. In an audio workflow, XML can describe fields such as filename, duration, codec, bitrate, sample rate, channel count, album, artist, timestamps, or processing history.

XML is readable by cataloging systems, databases, media pipelines, and custom software. It is also easy to validate against a schema and exchange between operating systems. XML does not define one universal way to store playable AAC or PCM audio, so an application that requests “AAC in XML” must specify its XML schema.

How to actually convert AAC to XML

For standard metadata extraction, FFmpeg’s ffprobe is the most direct desktop method:

1. Install FFmpeg from a trusted package for your operating system.
2. Open a terminal in the folder containing the AAC file.
3. Run ffprobe -v quiet -print_format xml -show_format -show_streams input.aac > output.xml.
4. Open output.xml in a text editor or XML application and check the generated <format> and <stream> elements.

The resulting XML can include the AAC codec, duration, file size, bitrate, sample rate, channel layout, stream index, and container information. If the source is an MPEG-4 file, replace input.aac with its actual filename, such as recording.m4a.

To produce a smaller XML document containing selected fields, use FFprobe’s individual options and redirect the result, then transform or filter the XML with an XML processor. FFprobe’s output is descriptive; it does not embed the AAC audio data in the XML.

For a no-installation conversion, upload the AAC file to the AAC-to-XML converter on 101convert.com, choose XML as the target format, and download the generated file. Check the resulting XML against the receiving application’s required tags because XML output structures are application-specific.

If another program requires audio samples inside XML, determine its schema before converting. A custom script may decode AAC to PCM with FFmpeg and write samples as numeric elements or Base64 data, for example with ffmpeg -i input.aac -f s16le -; this is not a standardized AAC-to-XML format and usually produces files much larger than the original.

Quality, compatibility, and limitations

Metadata extraction does not re-encode the audio, so the AAC stream’s quality remains unchanged. XML containing only metadata cannot be played by an audio player and cannot replace the original AAC file.

Tags may be absent or inconsistent in raw .aac files, especially compared with tagged .m4a files. AAC profiles, ADTS headers, MPEG-4 container metadata, Unicode characters, and album-art attachments may not map cleanly to a receiving XML schema.

Use UTF-8 XML and preserve the original AAC alongside output.xml. If an application rejects the file, compare its required element names, namespaces, date format, duration units, channel notation, and whether it expects metadata only or embedded audio data.