Compress Video
Compress your videos to reduce file size while maintaining quality. Perfect for sharing, email attachments, or saving storage space.
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Why video files are so large, and what compression changes
Uncompressed video is absurd — a minute of 1080p at 30 frames per second is several gigabytes. Every video you have ever watched is heavily compressed, and modern codecs do it by exploiting redundancy between frames: most of the picture does not change from one frame to the next, so a codec stores full keyframes occasionally and only the differences in between.
Three dials control the size. Bitrate is the data budget per second and the dominant factor. Resolution is the pixel dimensions — dropping from 4K to 1080p removes three quarters of the pixels. Codec choice matters too: H.265 and VP9 achieve roughly half the size of H.264 at the same quality, at the cost of slower encoding and slightly narrower compatibility. Frame rate is the fourth lever, and halving 60fps to 30fps is often invisible for screen recordings and talking heads.
Why we built this tool
The trigger is nearly always a limit: an email attachment, a messaging app that refuses anything over a certain size, a slow upload, or a platform that rejects long files.
Videos are personal — family footage, screen recordings of internal systems, unreleased marketing material. Uploading a 500 MB file to a compression site means a long wait and a full copy of your footage on someone else's disk, and free services usually cap the size or stamp a watermark on the output. Ours runs FFmpeg compiled to WebAssembly directly in your browser: the encoding uses your own CPU, the file never leaves your device, there is no size limit, and no watermark is added.
Tips and common mistakes
- Reduce resolution before reducing quality — it is by far the larger saving.
- H.265 and VP9 give roughly half the size of H.264, at the cost of slower encoding.
- Halving 60fps to 30fps is invisible for screen recordings and talking heads.
- Encoding is CPU-heavy; expect a laptop to take several minutes on a long file and let it finish.
Quick start: using Compress Video
- Load the video you want to shrink.
- Lower the resolution first if it is larger than it needs to be — this is the biggest saving.
- Choose a bitrate or quality level, and a modern codec if your destination supports it.
- Start the encode and be patient; video compression is genuinely heavy work.
- Watch a section of the result at full screen before deleting the original.
Trim unnecessary footage first with Trim Video — shorter is a bigger saving than lower quality.