Compress Video

How compressing works

Drop a video in and it comes out as a smaller MP4. The slider sets the balance: further left gives a smaller file, further right keeps more detail. Because a video's picture has to be made again to change its size, this always takes longer than a fast repackage — watch the moving bar on each video while it works. If a video can't get any smaller at the chosen setting, you keep the original.

How to use it

1. Move the Quality slider. Left gives a smaller file, right keeps more detail.
2. Drop your videos onto the box, or press Choose videos.
3. Watch the bar on each video — a longer video takes longer to compress.
4. Press Save beside a video when it says Compressed.

Questions people ask

How does it make the file smaller?

It makes the picture again at a lower quality setting, the same idea as Compress Photo but for every frame of the video. A lower setting throws away more fine detail, so the file gets smaller.

Which quality setting should I use?

The middle, “balanced” setting suits most videos. Move it left if the file still needs to be smaller, or right if you see the picture losing quality.

Why is this slower than MOV to MP4?

MOV to MP4's fast choice only changes the wrapper around the video, so it takes seconds. Compressing has to remake the picture itself to shrink it, which takes real time — longer for a longer or higher-resolution video.

What if the file is already small?

If compressing it again would make it bigger than it already is, the tool keeps your original and tells you so.

Does the sound change?

Usually not — the sound is kept as it is. It is only remade if your browser can't put its exact kind of sound into an MP4.

Is there a size limit?

Up to 2 GB per video. The video is held in your computer's memory while it is compressed, so very large videos need a computer with plenty of memory.

Is my video uploaded?

No. Everything happens inside your own browser.