#   Media Codec & MIME Type Fingerprint 

 Test which audio and video codecs your browser supports. Codec support varies significantly across browsers and devices, making it a useful fingerprinting vector.

   Data stored in `window.fingerprint.codecs`  

 

 ##### What are Media Codecs?

 Media codecs compress and decompress audio/video data. Support varies by browser, OS, and hardware. Trackers use codec combinations to identify devices, especially AV1, HEVC, and Opus support which indicates newer hardware.

  Also check our [WebRTC Leak Test](https://scrapfly.io/web-scraping-tools/webrtc-leak) for real-time communication fingerprinting and IP leak detection.

 

  ### Summary & Global Hash

 Codec support overview and combined fingerprint 

 

  0

Video Codecs

 

 

 0

Audio Codecs

 

 

 0

API Tests

 

 

 0

WebRTC Codecs

 

 

 

 ###   Global Fingerprint 

 Computing... 

  Combined hash of all codec support

 

 

 

  ### Video Codecs

 Supported video compression formats 

 `Computing...` 



 

 

  ### Audio Codecs

 Supported audio compression formats 

 `Computing...` 



 

 

  ### Codec API Support Matrix

 Comprehensive codec support across HTMLMediaElement, MediaSource, and MediaRecorder APIs 

 `Computing...` 



 

 

  ### WebRTC Codecs

 Real-time communication codec capabilities via RTCRtpSender/Receiver 

 `Computing...` 



 

 

  ### How Codec Fingerprinting Works

 

 

  Why Codec Support Matters for Tracking  

 Different browsers, operating systems, and hardware support different codec combinations. For example:

- **AV1 support** indicates a newer browser or recent OS update
- **HEVC (H.265)** is supported on Apple devices but rarely on Windows/Linux
- **Opus** is supported on Firefox/Chrome but not older browsers
- **FLAC** support varies significantly across platforms
 
 By testing dozens of codec combinations, trackers can narrow down your exact browser, OS version, and sometimes even hardware model.

 

 

  Entropy Analysis  

 Codec fingerprinting provides **moderate entropy** (4-8 bits typically). While not as unique as Canvas or WebGL, it's still valuable because:

- It's extremely stable since codec support doesn't change unless you update your browser/OS
- It's difficult to spoof without breaking media playback
- It correlates with other signals (OS, hardware, browser version)
- Testing is fast and doesn't require user permission
 
 

 

  Protection Methods  

 Codec fingerprinting is difficult to prevent because:

- Blocking codec detection breaks video/audio playback
- Spoofing codec support can cause media errors
- Privacy browsers (Tor, Brave) normalize codec support, but this may reduce functionality
 
 **Best practices:** Use privacy-focused browsers with fingerprint resistance, keep software updated to match common configurations, and avoid browser extensions that add unusual codec support.