Compress Video · MP4

How to compress a video online (free)

1. Drop your video onto the box above, or click to choose one.
2. Pick a mode: Quality for a simple good/smaller trade-off, or Target size to fit under a hard limit in megabytes. Optionally lower the resolution or remove audio for an even smaller file.
3. Click Compress. The first run downloads the FFmpeg engine once (which the browser then caches), after which encoding begins. Download the MP4 result when it finishes.

Compress a video to a target size (Discord, email, uploads)

Switch to Target size and type a limit — say 10 MB for a Discord upload, 25 MB for an email attachment, or whatever a form allows. The tool reads your video's length, works out the bitrate that fits under your number (leaving a small safety margin and accounting for the audio track), and re-encodes to match. The result lands just under your limit rather than wildly over or under it.

Quality mode and how it works

Quality mode uses constant-quality encoding (CRF) instead of a fixed size. Higher quality keeps more detail at a larger size; Balanced is a sensible default; Smaller file and Smallest trade visible detail for size. This is the best choice when you care about how the video looks rather than hitting an exact file size.

Real FFmpeg, running in your browser

This tool ships FFmpeg compiled to WebAssembly, the same encoder used by professional video pipelines, and outputs a widely compatible MP4 (H.264 video, AAC audio). Because it runs inside your browser tab, your video is never uploaded: there is nothing to leak, cache on a server, or delete later. The trade-off is speed — your own device does the encoding, so longer or higher-resolution videos take longer than they would on a dedicated server.

Is it really private?

Yes. There is no upload step and no account. You can open your browser's network tab and watch: after the one-time engine download, no request carries your video data. The tool works offline once the page and engine have loaded.

What's the largest video I can compress?

Everything happens in memory in your browser, so very large files (multiple gigabytes) can run out of memory depending on your device. It's designed for clips and typical recordings rather than feature-length footage. If a large file fails, try lowering the resolution or trimming it first.