Video Compressor
Video Compressor
What is this tool?
A browser-based video compressor built on ffmpeg.wasm. It re-encodes the picture with x264 at a constant quality level, scales the height down to 1080p, 720p or 480p if you ask, and re-encodes the sound as AAC at the bitrate you pick (or drops it entirely). Everything runs on your own device, so nothing is uploaded and nothing is watermarked — the price is that your computer, not a server, does the encoding.
When to use it
- A clip is too large for WhatsApp, Telegram or an email attachment
- A screen recording has to fit a site's upload limit
- A 4K phone video needs to become a reasonable 1080p or 720p file
- You want a smaller preview copy and have to keep the original private
- A video needs to start playing quickly on a web page
How to use it
- 1Drop in a video — its size, resolution and length are read straight away
- 2Choose a compression level: Light, Balanced or Strong
- 3Cap the resolution if the source is larger than you need — this is usually the biggest saving
- 4Pick an audio bitrate, or turn the audio off
- 5Click Compress Video, compare the two players, and download the MP4
Frequently asked questions
Why is it slower than an online compressor?
Because the encoding happens on your device instead of a server farm, in a single-threaded WebAssembly build of ffmpeg. Expect roughly one to three times the clip's length, and keep the tab open while it works. In exchange, your video is never uploaded.
How much smaller will the file be?
Balanced at 720p typically cuts a phone recording to a fraction of its size. A clip that is already heavily compressed may barely shrink — the tool shows the real before and after sizes and tells you when there was nothing to gain.
What formats can I use?
Anything ffmpeg can read — MP4, MOV, WebM, MKV, AVI and more. The output is always an MP4 with H.264 video and AAC audio, which plays on practically every device.
Is there a file size limit?
No fixed limit, but a browser tab has finite memory. Very large files (well over a few hundred megabytes) may run out of it — a shorter clip or a lower output resolution is the fix.