← Back to MIME types
MIME Type
audio/aac
AudioMIME type for AAC audio files, widely used in streaming and mobile devices.
MIME type reference, HTTP example, browser usage, common mistakes, and related content.
What is the audio/aac MIME type?
The MIME type audio/aac is used to tell browsers, APIs, and servers how a file or response body should be interpreted.
MIME stands for Multipurpose Internet Mail Extensions, and MIME types are now a standard part of HTTP responses and web content delivery.
When a browser or client receives a response with audio/aac, it uses that information to decide how the content should be processed, rendered, downloaded, or executed.
Example
Content-Type: audio/aac
HTTP example
HTTP/1.1 200 OK Content-Type: audio/aac Content-Length: 1256
Common file extensions
.aac.m4a
Common use cases
- Mobile audio streaming
- Podcast and music delivery
- Audio in video containers
Common mistakes
- Using the wrong MIME type for the file being served
- Returning text/plain instead of audio/aac
- Forgetting required parameters like charset when relevant
- Using a deprecated MIME type in older server configurations
- Serving assets with a mismatched Content-Type header, causing browser parsing issues
How browsers use it
Browsers use the Content-Type response header to decide how a response should be handled. For example, HTML is rendered as a page, CSS is parsed as styles, JavaScript is executed as script, and images are displayed visually. If the MIME type is incorrect, the browser may refuse to load the file correctly or may treat it as plain text or a download instead.
Browser support
Strong support in all major modern browsers and natively on iOS and Android devices.
Practical developer insight
AAC is the default audio format for Apple devices and is widely used in MP4 video containers. It offers better quality than MP3 at similar bitrates and has strong browser support. Note: .m4a files are often served with audio/mp4 depending on the container.