Video Compressor

What it's for

Make a video small enough for wherever it’s going, such as an email that stops at 20 or 25 MB, or an upload form with a limit, without installing an app or uploading the video anywhere.

For example, when a three-minute phone video is 180 MB and has to go by email, choose it, keep Fit in at 20 and choose Make it smaller: you get an MP4 of under 20 MB at a resolution that suits that size.

How to use it

Choose an MP4 or MOV video, or drop it on the page, type the size it must fit in under Fit in (MB), and choose Make it smaller. The size and Picture at most are remembered in this browser.

The size sets the bitrate: what’s left once the sound is counted, spread over the video’s length. The resolution then follows from it: 1080, 720, 540 or 360 lines on the shorter side, whichever is largest and still sharp at that bitrate, never larger than the original. Choose a limit under Picture at most to keep it smaller than that. The picture is decoded and re-encoded as H.264, which plays everywhere, and the sound is copied as it is.

It takes a while for a long video, and the message shows how far it has got. The copy is saved as <name>-smaller.mp4 (or .mov), and the message gives its size, resolution and bitrate.

Example

Record a minute of your screen with the Screen Recorder, saved as MP4 without sound, and open it here with Fit in set to 5. The message reports a size just under 5 MB, a resolution of 960 × 540 for a widescreen recording, and a bitrate of about 0.6 Mbit/s.

Good to know

The video must be H.264 or HEVC (as phones, cameras and most screen recorders make), in an MP4 or MOV; WebM and other formats aren’t read. HEVC can be read only by browsers that decode it (Safari, and Chrome on most recent computers). A very short limit for a long video can’t be met: below about 150 kbit/s the tool says so rather than making something unwatchable, so trim the video first.

The size is a target, usually met with a little to spare; check the size in the message before you send it. Re-encoding loses some detail, so keep the original, and watch the copy through. Chapters, captions in the file and extra tracks aren’t kept, and a phone’s location and camera details aren’t copied. Nothing is uploaded.