clipstool
Nothing leaves your device

smaller file

Video compressor that runs on your own machine

Compress an MP4 or any other clip to fit an email cap, a chat limit or an upload ceiling. Pick how aggressive to be and the file shrinks accordingly.

Drop a video file here
MP4, MOV, MKV, WebM — all accepted
File
Size
Duration
Resolution
OutputMP4 · H.264 · AAC
Loading encoder…0%

Files are processed on your device · nothing is uploaded, stored or logged

How it works

  1. Pick your file. The browser reads it straight from disk. There is no upload progress bar, because there is no upload.

  2. The encoder loads once. A WebAssembly build of FFmpeg, around 30 MB, downloads the first time you use the site and stays cached afterwards.

  3. Your processor does the work. Everything happens in this tab, at roughly half of real time on a modern laptop.

  4. Save the result. The finished file is assembled in memory and handed to your downloads folder.

How the size actually comes down

Compression works by throwing away detail the eye is least likely to miss — fine texture in fast motion, subtle gradients in dark areas. The harder you push, the more of it goes.

The setting here controls that trade directly. Light typically cuts a file to around half its size with nothing visible lost. Balanced lands nearer a quarter and holds up fine for anything watched on a phone. Heavy will get almost any clip under a messaging limit, at the cost of visible softness in busy scenes.

Resolution is untouched — a 1080p video stays 1080p. Only the amount of data describing each frame changes.

If it is still too big

Trim the clip before compressing. Length affects file size more directly than any quality setting, so cutting thirty seconds off the front usually beats another round of compression. Screen recordings are the exception: they compress extraordinarily well because so much of the frame stays still.

Common questions

How small will my file get?

It depends heavily on the source. Phone footage typically drops 50–75 percent at Balanced. Screen recordings often shrink by 90 percent or more.

Does the resolution change?

No. The dimensions stay exactly as they were. Only the compression level changes.

Can I compress an already-compressed file?

Yes, but returns diminish fast and artefacts stack up. Going back to the original source gives a better result.

Why does it take longer than the other tools?

Compression genuinely re-encodes every frame, unlike the container conversions which often just repackage.

Related tools

Compress for Discord Change resolution Video trimmer WebM to MP4 MOV to MP4 MKV to MP4