WebCodecs Codec Support Dataset This dataset contains real world audio and video codec support data from over 1,142,586 real user sessions at free.upscaler.video using the WebCodecs API to detect both encoding and decoding support for over 1000+ codec variants across the following audio and video codecs: Video: h264 h265 vp8 vp9 av1 Audio: aac pcm opus vorbis mp3 flac The data is compiled and summarized on the project website ,webcodecsfundamentals.org, which provides a global overview of real world support for codecs like AV1 or h265, across operating systems and browsers. This dataset contains the underlying data used, with 363 million codec compatability tests from unique 1.14 million user sessions. CSV SCHEMA timestamp - ISO 8601 timestamp of when test was performeduser_agent - Full browser user agent stringbrowser - Browser family (Chrome, Safari, Edge, Firefox, Unknown)platform_raw - Raw platform identifier from navigator.platformplatform - Normalized platform (Windows, macOS, iOS, Android, Linux)codec - WebCodecs codec string tested (e.g., "av01.0.01M.08")encoder_supported - Whether VideoEncoder supports codec (true/false)decoder_supported - Whether VideoDecoder supports codec (true/false/empty) EXAMPLE ROWS2026-01-05T00:54:11.570Z,"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36...",Edge,Win32,Windows,av01.0.01M.08,true,2026-01-16T23:58:08.560Z,"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36...",Chrome,Win32,Windows,avc1.64040c,false,true Note: decoder_supported is empty for sessions before Jan 14, 2026. The secondexample shows a codec that can decode but not encode. QUICK STATSTotal Tests: 363,330,358Sessions: 1,142,586Unique Codecs: 1,087Collection Period: January 2026 - March 2026Data Source: free.upscaler.videoEncoder Data: All 1,142,586 sessionsDecoder Data: Sessions from Jan 14, 2026 onwards PLATFORM NORMALIZATIONThe 'platform' column applies the following normalization: Win32, Win64 → Windows MacIntel → macOS iPhone, iPad → iOS Linux armv8*, Android* → Android Linux x86_64, Linux aarch64 → Linux The 'platform_raw' column contains the original navigator.platform value. LICENSECreative Commons Attribution 4.0 International (CC-BY 4.0) You are free to:- Share and redistribute in any format- Adapt, remix, and build upon the data- Use commercially Under the following terms:- Attribution: Credit "upscaler.video Codec Support Dataset" with link Full license: https://creativecommons.org/licenses/by/4.0/