MP4 — The Universal Standard
MP4 (MPEG-4 Part 14) is the most widely used video format in the world.
- Compatibility: Plays on virtually every device and player
- Compression: Excellent quality-to-file-size ratio (H.264/H.265 codecs)
- Contains: Video + audio in a single file
- Best for: General use, sharing, archiving, any device
Verdict: If you're unsure which format to pick, MP4 is always the safe choice. It's the default for YouTube downloads on YTDownload.us.
WebM — The Web-Optimized Format
WebM is Google's open-source video format designed for web use.
- Compatibility: Chrome, Firefox, Edge, Opera (not natively in Safari/iOS)
- Compression: VP8/VP9 codecs, very efficient
- Best for: Web embedding, online streaming
- Downsides: Limited device support compared to MP4
M4A — Audio Extraction Format
M4A is an audio-only container format using AAC encoding.
- Compatibility: iPhone, iPad, Android, Windows, Mac
- Quality: Better than MP3 at the same bitrate
- Best for: Music, podcasts, audio downloads
- File size: Typically 3-8 MB per song
Format Comparison Table
| Format | Type | Compatibility | Quality | File Size |
|---|---|---|---|---|
| MP4 | Video+Audio | ✅ Universal | ✅ Excellent | Medium |
| WebM | Video+Audio | ⚠ Limited | ✅ Good | Small |
| M4A | Audio only | ✅ Wide | ✅ Excellent | Very Small |
| MKV | Video+Audio | ⚠ Limited | ✅ Excellent | Large |