Compress a video to a target size
Compress a video to hit a precise file size (for example to meet an email or platform upload limit). The bitrate is calculated automatically from the video's duration, entirely in your browser.
How it works
The tool calculates the video bitrate needed to reach the desired size by dividing the target size by the video's duration, then encodes the file in two passes at that bitrate for a better distribution of quality over time.
Is the result exactly the size I asked for?
No, it's an approximation: the bitrate calculation is an estimate based on the duration and a 5% safety margin, but the encoder may slightly overshoot or fall short of the target depending on the complexity of the content (motion, detail). Expect a deviation of a few percent around the target value.
Why two-pass encoding?
The first pass analyzes the video's complexity frame by frame, which lets the second pass distribute the available bitrate intelligently: more bits on complex scenes, fewer on static ones, for better perceived quality at the same size than single-pass encoding.
What happens if my target size is too small?
If the calculated bitrate gets very low, video quality can degrade sharply (blur, compression artifacts). The tool applies a minimum bitrate floor to avoid a completely unusable file, but below a certain threshold you're better off reducing the resolution or length of the source video.
100% local processing: compression runs entirely in your browser via WebAssembly, and your video is never sent to a server.