Where the time goes
Editing a video means rebuilding it. Every frame is decoded, changed — cropped, captioned, watermarked, resized — and compressed again, then the sound is added back. A minute of video at 30 frames a second is 1,800 frames. Ten minutes of 1080p is 18,000 frames of about two million pixels each.
All of it happens on your own device. That is why your video is never uploaded, and it also means there is no upload or download to wait for: the time you see is the work itself.
What sets the speed
- Length and resolution. Twice as long takes about twice as long. 4K has four times the pixels of 1080p.
- Your device. The browser hands the compression to your graphics hardware where it can. A recent computer is many times faster than an older phone.
- How the video is read. Most video tools step through the video in the browser’s own player, one frame at a time, and that is often the slowest part of the job. The Video Compressor reads an MP4 straight from the file instead, which is quicker.
- Whether the tab is in front. Browsers slow down pages you are not looking at, and a phone pauses them when the screen locks.
How to make it quicker
- Cut away what you do not need first with the Video Trimmer.
- Choose a lower output resolution where the tool offers one. 720p is plenty for most social posts.
- Keep the tab in front, and keep a phone’s screen on.
- Close other heavy tabs, and plug a laptop in: many slow down to save battery.
If the progress stops altogether rather than moving slowly, see Video export stopped or the tab crashed.