The result depends on the source codec, resolution, movement, and duration. Trimming and lowering a 1080p or 4K source to 720p usually has the largest effect.

Will compression reduce quality?

All meaningful video compression trades some detail for a smaller file. Use Light to preserve more detail, or Balanced for everyday sharing.

What format will I download?

The compressed file is an MP4 using H.264 video and optional AAC audio for broad compatibility.

Can I compress a video on iPhone or Android?

Yes. Modern mobile browsers are supported, although long or high-resolution videos take more memory and time than short clips.

Is the video sent to a server?

No. Compression happens locally in your browser, and the video stays on your device.

Compress Video Without Uploading It

Reduce the size of MP4, MOV, M4V, or WebM video directly in your browser. The output is a broadly compatible MP4, and the original video never leaves your device.

How to Reduce Video File Size

Choose your video: add a file up to 100MB.
Trim first: remove footage you do not need for the biggest size reduction with the least quality loss.
Choose compression and resolution: Balanced at 720p works well for messaging and social sharing.
Download the MP4: compare its size with the original and keep the version that suits your use.

Which Compression Setting Should I Use?

Light: for archiving or editing when visual quality matters most.
Balanced: for WhatsApp, email, websites, and most social posts.
Strong: for strict upload limits or quick sharing on slower connections.

Resolution and duration usually affect file size more than any single quality switch. A short 720p video will normally be much smaller than a long 1080p video.

Private Browser-Based Compression

Many online compressors send personal videos to a remote server. This tool uses FFmpeg WebAssembly locally instead, so there is no upload queue, account, or watermark.