OneTaskBy Tim King · Updated
Video Compressor
Reduce Video File Size to a Target MB for Email, See the Saving First
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How the Video Compressor works
This video compressor shrinks a clip to a file size you choose. Type a target in megabytes, such as 25 for an email attachment or 10 for a chat app, press Render and download the smaller video. The page works out the bitrate from the clip's length. Nothing is uploaded.
Video compressor: size comes from bitrate and length
A video's file size is roughly its bitrate multiplied by its duration. A 2-minute clip at 8 megabits per second is about 120 MB; at 1.5 megabits it is about 22 MB. So instead of guessing at a quality slider, the page divides your target size by the clip's length, keeps 5% back for the container and sets aside 128 kilobits per second for sound. What is left goes to the picture.
When to lower the resolution too
Squeezing a 4K clip into a few megabytes at full resolution spreads too few bits over too many pixels, and the picture turns to blocks. Dropping to 720 or 480 lines gives each pixel more data and usually looks better at the same size. As a rough guide, 720p needs about 1.5–2.5 megabits per second to look clean and 480p about 0.8–1.2. The results panel shows the bitrate you got.
Common size limits
Email providers commonly cap attachments at 20–25 MB. Discord's free tier allows 10 MB per file. WhatsApp limits shared video to around 16 MB on many devices. Leave a little headroom below each limit, since browsers' encoders do not hit a bitrate exactly.
What to expect
Compression plays the video through once, so a 3-minute clip takes 3 minutes. The output is WebM in Chrome, Edge and Firefox and MP4 in Safari. If the target is too small for the length, the page says so rather than producing an unwatchable file. Cut the clip with the video trimmer or split it with the video splitter and try again.
FAQ
Why is my compressed file slightly bigger than the target?
Browser encoders aim for an average bitrate and can overshoot on busy scenes. The page warns you when that happens. Set the target a few megabytes under the real limit, or lower the resolution for more headroom.
Why does the page say the target is too small?
Below about 100 kilobits per second for the picture, video is no longer watchable. A long clip with a small target hits that floor. Lower the resolution, remove the sound, or trim the video first to make the numbers work.
Does removing the sound help much?
It frees 128 kilobits per second for the picture. On a short clip with a small target that is a noticeable gain; on a long, high-bitrate clip it makes little difference to the overall size.
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