Why videos are big, and how to make them smaller
One minute of phone video can be 100 MB or more. Knowing what drives the size helps you pick settings that keep it watchable.
Open the tool: Video Compressor
The formula
File size (MB) ≈ bitrate (Mbit/s) × length (seconds) ÷ 8. A phone records 1080p at 15-20 Mbit/s and 4K at 40-60 Mbit/s, which is why a 1-minute clip reaches 150-450 MB. Compressing means choosing a lower bitrate, and with it a resolution that still looks good at that bitrate.
Bitrate guide for H.264
| Resolution | Good quality | Acceptable |
|---|---|---|
| 1080p | 5-8 Mbit/s | 3 Mbit/s |
| 720p | 2.5-4 Mbit/s | 1.5 Mbit/s |
| 480p | 1-1.5 Mbit/s | 0.7 Mbit/s |
| 360p | 0.6-0.8 Mbit/s | 0.4 Mbit/s |
Codecs
- H.264 (AVC): plays everywhere. The safe choice for sharing.
- HEVC (H.265): about 40% smaller at the same quality; used by iPhones, but not every device plays it.
- VP9 and AV1: efficient and open; AV1 is the smallest but needs new hardware to encode quickly.
Other ways to save space
- Trim the start and end: every second costs the same.
- Use 30 fps instead of 60 fps for talking or slow scenes.
- Remove the sound if it isn't needed.
- Avoid shaky footage and confetti: lots of motion needs more bitrate.