Video Downloading Explained: Formats, Quality, and Tools
· 10 min read
Video Containers
A container is the file format that packages video, audio, subtitles, and metadata together. The container does not determine quality — that is the codec's job.
| Container | Extension | Video Codecs | Browser Support | Best For |
|---|---|---|---|---|
| MP4 (MPEG-4) | .mp4 | H.264, H.265, AV1 | All browsers | Universal compatibility |
| WebM | .webm | VP8, VP9, AV1 | Chrome, Firefox, Edge | Web streaming |
| MKV (Matroska) | .mkv | Any codec | None natively | Archiving, multiple audio/subtitle tracks |
| AVI | .avi | Any codec | None | Legacy compatibility |
| MOV | .mov | H.264, ProRes | Safari | Apple ecosystem, editing |
For maximum compatibility, MP4 with H.264 video and AAC audio works on virtually every device and browser. Use our Video Info tool to inspect any video file's format details.
Video Codecs
A codec compresses raw video data. Better codecs achieve smaller files at the same quality, but require more processing power to encode and decode.
| Codec | Year | Efficiency vs H.264 | Encoding Speed | Hardware Decode |
|---|---|---|---|---|
| H.264 (AVC) | 2003 | Baseline | Fast | Universal |
| H.265 (HEVC) | 2013 | ~40% smaller | Slow | Most modern devices |
| VP9 | 2013 | ~35% smaller | Slow | Chrome, Android, some TVs |
| AV1 | 2018 | ~50% smaller | Very slow | Newest devices (2022+) |
YouTube uses VP9 for most content and AV1 for newer uploads. Netflix uses H.265 and AV1. Most downloaded videos are H.264 in MP4 for compatibility.
Resolution and Quality
| Name | Resolution | Pixels | Typical Bitrate | 10 min File Size |
|---|---|---|---|---|
| 360p | 640×360 | 230K | 1 Mbps | ~75 MB |
| 480p (SD) | 854×480 | 410K | 2.5 Mbps | ~190 MB |
| 720p (HD) | 1280×720 | 922K | 5 Mbps | ~375 MB |
| 1080p (Full HD) | 1920×1080 | 2.1M | 8 Mbps | ~600 MB |
| 1440p (2K) | 2560×1440 | 3.7M | 16 Mbps | ~1.2 GB |
| 2160p (4K) | 3840×2160 | 8.3M | 35 Mbps | ~2.6 GB |
Higher resolution does not always mean better perceived quality. On a phone screen, 720p and 1080p look nearly identical. Resolution matters most on large displays.
Bitrate Explained
Bitrate is the amount of data per second of video. It is the single biggest factor in file size and quality.
- CBR (Constant Bit Rate) — Same bitrate throughout. Predictable file size but wastes bits on simple scenes.
- VBR (Variable Bit Rate) — Allocates more bits to complex scenes (action, motion) and fewer to simple ones (static shots). Better quality per byte.
- CRF (Constant Rate Factor) — Targets a consistent quality level. The encoder decides the bitrate per frame. Best for offline encoding.
YouTube's recommended upload bitrates: 1080p at 8 Mbps (SDR) or 10 Mbps (HDR), 4K at 35-45 Mbps.
Audio in Video Files
| Codec | Quality | Typical Bitrate | Compatibility |
|---|---|---|---|
| AAC | Good | 128-256 kbps | Universal |
| MP3 | Good | 128-320 kbps | Universal |
| Opus | Excellent | 64-128 kbps | WebM, modern browsers |
| FLAC | Lossless | 800-1400 kbps | MKV, limited browser |
| AC3 (Dolby) | Good | 384-640 kbps | MKV, home theater |
For extracting audio from video, use our Video to Audio tool. For cutting audio clips, try Audio Cutter.
Choosing the Right Format
| Use Case | Container | Video Codec | Audio | Resolution |
|---|---|---|---|---|
| Share on social media | MP4 | H.264 | AAC 128k | 1080p |
| Archive/backup | MKV | H.265 or AV1 | FLAC | Original |
| Web embedding | MP4 + WebM | H.264 + VP9 | AAC + Opus | 720p-1080p |
| Mobile viewing | MP4 | H.264 | AAC 128k | 720p |
| Editing | MOV | ProRes/DNxHR | PCM | Original |
FFmpeg Quick Reference
# Convert to MP4 (H.264 + AAC)
ffmpeg -i input.mkv -c:v libx264 -crf 23 -c:a aac -b:a 128k output.mp4
# Extract audio only
ffmpeg -i video.mp4 -vn -c:a libmp3lame -b:a 192k audio.mp3
# Resize to 720p
ffmpeg -i input.mp4 -vf scale=-1:720 -c:v libx264 -crf 23 output_720p.mp4
# Convert to WebM (VP9 + Opus)
ffmpeg -i input.mp4 -c:v libvpx-vp9 -crf 30 -b:v 0 -c:a libopus output.webm
# Trim without re-encoding (fast)
ffmpeg -i input.mp4 -ss 00:01:00 -to 00:02:30 -c copy trimmed.mp4
# Get video info
ffprobe -v quiet -print_format json -show_format -show_streams input.mp4Frequently Asked Questions
What is the difference between a codec and a container?
A codec (H.264, H.265, VP9, AV1) compresses and decompresses the video data. A container (MP4, MKV, WebM) is the file format that holds the video stream, audio stream, and metadata together. Think of the container as a box and the codec as how the contents are packed.
Which video format has the best quality?
At the same bitrate: AV1 > H.265/HEVC > VP9 > H.264. However, H.264 in MP4 has the widest compatibility across devices and browsers. Choose based on your target audience's devices.
What resolution should I download?
For phones: 720p is sufficient and saves storage. For laptops and monitors: 1080p. For 4K displays: 2160p. Higher resolution means larger files — 4K is roughly 4x the size of 1080p.
Why is my downloaded video so large?
File size depends on resolution, bitrate, duration, and codec. A 10-minute 4K video at 20 Mbps is about 1.5 GB. To reduce size: lower the resolution, choose a more efficient codec (H.265 or AV1), or reduce the bitrate.
What is the difference between CBR and VBR?
CBR (Constant Bit Rate) uses the same bitrate throughout the video. VBR (Variable Bit Rate) allocates more bits to complex scenes and fewer to simple ones, resulting in better quality at the same average file size.