How it works
- Drop your video. MP4, MOV, WebM or MKV, any length. Pick Custom and type a size, or use a preset.
- Pick where it's going. The tool works out the bitrate from the length and the limit, keeps room for the sound, and picks a resolution and frame rate that will still look clean. The estimated size and a real before-and-after frame update as you change things.
- Trim if you like, or set the resolution and frame rate yourself.
- Compress. When the encode finishes, the tool weighs the file. If it came out over the limit, it encodes again at a lower bitrate, so the file you download is always under the target, to the byte.
What "without losing quality" really means
Every smaller file throws something away. The trick is to throw away what you won't notice. Phone and camera videos are recorded at very high bitrates, often 15 to 50 megabits a second, so they can usually shrink to a third of their size with no visible change. Past that, the choice is between fewer pixels and softer detail, and the tool makes that choice for you, with a preview to check it.
Where the savings come from
- Resolution. 4K to 1080p cuts the pixels by three quarters. On a phone screen you can't tell.
- Frame rate. 60 to 30 fps halves the frames. Fine for talking and slow scenes; keep 60 for games and sport.
- Bitrate. The tool spends exactly what your target allows and no more.
- Trimming. Every second you cut is bitrate for the seconds you keep.
- Sound. Audio gets 32 to 128 kbps depending on the room left. Remove it entirely for silent clips.
Tip: compare at the line between the halves of the preview. Look at faces, text and fine textures like grass or hair; that's where compression shows first.
Questions
Can I compress a video without any quality loss?
Not at a smaller size: smaller always means some information is removed. But high-bitrate phone and camera videos can usually shrink a lot before you can see any difference, and the preview lets you check.
What's a good size for a 1-minute 1080p video?
About 20 MB keeps 1080p at 30 fps looking clean. 10 MB works well at 720p.
Is my video uploaded?
No. Your browser reads the file from your disk and encodes it on your own device with WebCodecs. Nothing is sent to a server, so it also works on large private files.
Why does it say the file is guaranteed to be under the limit?
After encoding, the tool measures the real file. Video encoders can overshoot a bitrate by a few percent, so if the file is over the target the tool encodes again at a lower bitrate. It only offers the download once the byte count is under the target, and it shows both numbers.
Which browsers work?
Any browser with WebCodecs video encoding: recent Chrome, Edge, Firefox and Safari on a computer, and Chrome on Android. If yours can't, the tool says so instead of failing halfway. If your browser can encode VP9 but not H.264 with AAC, you get a WebM file and a note saying so.