Compress Video
Make a video smaller by lowering its resolution (1080p, 720p, 480p) and quality, or by setting a target size, and save it as H.264 MP4. The sound is kept as it is. Great for email and chat app limits, and your video is never uploaded.
Your files never leave this device. Everything is processed inside your browser and nothing is uploaded to a server.
When to use Compress Video
Fit email and chat app limits
When an attachment limit (such as 25 MB) or a chat app video limit gets in the way, enter a target size and shrink the video to fit. Lowering the resolution to 720p usually does it in one go.
Lighten 4K phone videos
Recent phones record 4K at several MB per second, so a few minutes can reach gigabytes. For viewing on phones and laptops, 1080p or 720p looks almost the same and takes a fraction of the space.
Shrink files for school or work
Fit a presentation recording or assignment video under a submission limit. For screen recordings with little motion, check in the preview that text is still readable even at low quality.
How to use the Compress Video tool
- Click "Choose a video file" or drag a video onto the page.
- Choose a resolution (original, 1080p, 720p or 480p), then choose a quality (high, medium or low) or enter a target size in MB. The bar shows the expected size.
- Click "Compress" and wait. It can take about as long as the video, and you can click "Stop" to cancel.
- Check how much smaller it got and click "Download".
Frequently asked questions
How does it make videos smaller?
Video size is mostly set by how much data is used per second (the bitrate). This tool saves the picture again with the video encoder built into your browser (WebCodecs), lowering the resolution and bitrate. Halving the resolution leaves a quarter of the pixels, so far less data is needed for the same quality.
Will it match the target size exactly?
The bitrate is set by dividing the size by the length, so it usually comes close, but the encoder uses more or less data depending on the scene, so it may land a little above or below. If you have a hard limit, aim about 10% lower. 1 MB is counted as 1,000,000 bytes (slightly less than places that count 1,048,576). If the result is not smaller than the original, you are told instead of getting the file.
What format is it saved in?
The picture is saved as H.264 in an MP4 file, which opens on phones, computers and chat apps. If this browser cannot save H.264, it saves VP9 in WebM and tells you beforehand. The sound is moved over without re-encoding whenever possible.
Which browsers does it work in?
Re-encoding needs the WebCodecs built into the browser. It works in Chrome and Edge 94+, Safari 16.4+ and Firefox 130+ on desktop. If the device cannot save a size (for example 4K on some phones), that resolution is marked and cannot be chosen. Computers are much faster than phones.
How long does it take?
Every frame is decoded and saved again, so it takes from a fraction of the video length to several times longer depending on the device. Progress and time left are shown, and lower resolutions are faster. It keeps going in another tab, but it may pause if the device goes to sleep.
What gets downloaded?
When you first open a video, the page loads a program that reads and writes video files (mediabunny, about 120 KB compressed) from this site. Decoding and saving are done by the WebCodecs built into your browser, and your video is never uploaded. mediabunny is open source under the Mozilla Public License 2.0; the license text and source information are at justus.ing/vendor/mediabunny/README.txt.
Is my video uploaded?
No. Reading and saving the video both happen in this browser, so even large videos start right away with no upload time.
Are my files uploaded to a server?
No. Files are processed only inside your browser and are never sent to any server. Only the code and character mapping data needed for processing are downloaded from this site; your files themselves never leave your device. You can check this yourself in the Network tab of your browser's developer tools.
Are my files safe even with ads on the page?
Yes. Ads only run outside the tool area. The tool area, where you choose and process files, is an isolated space your browser keeps separate, so other scripts on the page, including ads, cannot read your file content or file names. The tool area is blocked from connecting anywhere other than this site. When you drag a file onto the page, the tool area expands to fill the screen so the isolated space receives the file.