Compress Video Online
Shrink video file size by up to 90% without an upload — your file never leaves your device.
Phone cameras and screen recorders produce huge files — a one-minute 4K clip can easily be 400 MB. This compressor re-encodes your video with the modern H.264 codec at an efficient quality level, typically cutting file size by 70–90% while keeping it looking sharp on a phone or laptop screen.
Because compression happens in your browser via WebAssembly, there's no upload step: a 1 GB file starts compressing immediately instead of spending twenty minutes uploading first. Choose a compression level, optionally cap the resolution, and download a much smaller MP4.
How to compress video online
- 1Add your video by dropping it in the box or browsing for it.
- 2Pick a compression level — Balanced is right for most videos.
- 3Optionally lower the max resolution (720p roughly halves the size of a 1080p video).
- 4Click Compress Video, watch the progress bar, and download the smaller file.
Frequently asked questions
How much smaller will my video get?
It depends on how it was originally encoded. Phone footage and screen recordings usually shrink by 70–90%. Videos that were already tightly compressed (like clips downloaded from social media) shrink less.
Will compressing reduce the quality?
Slightly, by design — that's where the size savings come from. The Balanced setting (CRF 28) looks close to the original on most screens. If you see artifacts, re-run with the Light setting.
Is my video uploaded to a server?
No. SliceVideo runs FFmpeg compiled to WebAssembly inside your browser tab. The file never leaves your device, which is faster and more private than upload-based compressors.
What's the best setting for sending a video by email?
Most email providers cap attachments at 25 MB. Use Strong compression and 720p resolution; if the result is still too large, trim the video shorter first or use our Discord compressor, which targets an exact output size.
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