Codec Compatibility Guide
Because browsers rely on OS-level decoders, support varies. Here is exactly what will play.
Video Codecs (The Picture)
| Codec | Chrome / Edge | Firefox | Safari | Notes |
|---|---|---|---|---|
| H.264 (AVC) | Native | Native | Native | The universal standard. Hardware accelerated everywhere. |
| VP9 | Native | Native | Partial (macOS 11+) | Google's open standard. Excellent for 4K YouTube rips. |
| H.265 (HEVC) | Requires Extension | No | Native | Apple ecosystem loves this. Edge requires the $0.99 HEVC store extension. |
| AV1 | Native | Native | iOS 17+ / macOS 14+ | Next-generation royalty-free codec. Requires modern GPU for hardware accel. |
Audio Codecs (The Sound)
Universally Supported
- AAC: The standard for MP4 files. Works perfectly everywhere.
- MP3: Legacy standard. Works perfectly.
- Opus: Superior compression, standard in WebM and many new MKVs.
- FLAC: Lossless audio, natively decoded by modern browsers.
Problematic / Unsupported
- AC3 / E-AC3 (Dolby Digital): Licensing prevents browsers from shipping decoders. Read more.
- DTS / DTS-HD: Same as above. If your MKV uses this, you will get video but no audio.
- TrueHD: High-end uncompressed format, completely unsupported in web.
Workaround: Use a tool like Handbrake or ffmpeg to quickly transcode the audio track from AC3 to AAC without touching the video stream (`-c:v copy -c:a aac`).