Ten minutes of phone video, and the file is several gigabytes: too big to send, too big to store. This page explains why it's so big and how to shrink it, and when you shouldn't.
Why video files are so big
A video is many still images played in sequence: 30 per second, 1,800 per minute. The sharper the picture (higher resolution) and the more detail each image keeps (higher bitrate), the bigger the file. As a rough guide from phone settings pages, 1080p at 30fps is about 60 to 90 MB per minute and 4K at 30fps about 190 to 350 MB per minute, depending on the codec. So a ten-minute 4K clip running to several gigabytes is normal.
Three ways to shrink a file
- Lower the resolution: 4K to 1080p usually cuts the size a lot. On a phone you can barely tell; on a big TV you can.
- Lower the bitrate: same resolution, less detail per frame. A little is invisible; too much and you get blocky patches.
- Trim what you don't need: the most effective method and the kindest to quality. Cut the unused ten seconds at the start and the part where the camera was left running.
Free tools
- Computer: HandBrake is free for Windows and Mac. Pick a preset (for example Fast 1080p30) and start. On a Mac, QuickTime's Export can also output 1080p or 720p.
- Phone: set the camera to 1080p before shooting; easier than compressing afterwards. Use the built-in editor to trim the ends.
- Cloud: upload the original to Google Drive as it is; no need to compress first. See how to send us your material.
Does compressing make it blurry?
Yes, to varying degrees. Compression discards detail; a little goes unnoticed, a lot turns blurry or blocky. And every pass discards more: send through LINE, save, send again, and the quality drops each time. The rule: keep one original, and when you need a small file, compress from the original, never from an already compressed copy.
When you should never compress
- Footage going to an editor. Editing needs the most detail; send originals.
- Important videos for long-term keeping, such as weddings or your children.
- Videos whose use isn't decided yet. Keep the original; export the right version when the use is known.
Frequently asked questions
Why does video quality drop when sent through LINE or WhatsApp?
Messaging apps compress video heavily to send it fast. To send originals, use a cloud service like Google Drive or a cable to a computer.
Does compressing change the file format?
Most tools output MP4, the most compatible format.
How big should the finished edit be?
It depends on where it goes; social platforms, websites and on-site playback differ. At delivery we export the right version for each destination. See which delivery format to choose.
