Compress a video
Make a video a fraction of the size, or fit it under a limit like 10 MB for Discord or 25 MB for email. It is compressed on this device and never uploaded.
- Nothing is uploaded
- Works offline after first visit
- Open source
- No watermark · limit is your device’s memory; phones hold less
Makes MP4, MOV, WebM and MKV videos smaller and saves an MP4, either at a quality level or fitted under a size you pick: 8, 10, 16, 25, 50 or 100 MB. It is free, needs no account and adds no watermark, and your videos are not uploaded: your browser’s own video encoder re-encodes them on your device. The size limit is your device’s memory (phones hold less), and after one visit and a short wait the page works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
A worked example: a clip for Discord
Say a phone clip is 38 MB and Discord’s free limit is 10 MB. Drop it, set Compression to Fit a file size, pick 10 MB (Discord free) and press Compress. The page works out the bitrate from the video’s length and lowers the resolution if it has to. You get clip-compressed.mp4, and the result line lists its resolution, length and video codec. If it still comes out a little over, the line says so and suggests the next size down.
How it works
- Drop one or more videos (MP4, MOV, WebM or MKV), or tap to pick them.
- Choose how hard to compress, or Fit a file size and pick a limit such as 10 MB for Discord. Lower the resolution or remove the sound for even smaller files.
- Compress. Each video is re-encoded in your browser and saved as MP4; one downloads straight away, several download as a zip.
In your browser, not on a server
Mediabunny (MPL-2.0), a media toolkit written in TypeScript, reads the MP4, MOV, WebM or MKV container in your tab. Your browser’s own hardware-backed video decoder and encoder (WebCodecs) re-encode the picture at the bitrate and size you chose, H.264 where available and VP9 or AV1 otherwise, and the sound as AAC or Opus. Mediabunny then writes a new MP4 in memory. For a target size, the bitrate is worked out from the length of the video, and the resolution is lowered when a long video would otherwise turn to mush.
Compared with upload-based tools: Online compressors upload the whole video before they start, cap free files at a few hundred megabytes, and often add a watermark or a queue. Phone videos are some of the most personal files people have. Here the video never leaves your device, and a 2 GB file is compressed as fast as your computer can encode it.
Verify it yourself. Give the page a short while after one visit to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Can I compress a video without uploading it?
Yes. The video is read and re-encoded by your browser’s own video encoder inside this page. There is no server in the process, so there is no upload to wait for and no copy left on someone else’s computer. After one visit and a short wait you can switch off Wi-Fi and it still works.
How much smaller will it get?
Phone videos usually shrink to between a quarter and a tenth of their size on Balanced with little visible difference, because phones record at a very high bitrate to save battery. A video that was already compressed for the web will not shrink much, and the result then tells you it grew.
How do I get a video under 10 MB for Discord?
Choose Fit a file size and pick 10 MB. The page works out the bitrate from the length of the video and lowers the resolution if it needs to. About 1 minute fits at 720p; longer videos come out at lower resolutions, and very long ones are refused with how long a clip will fit.
Which file sizes can I fit a video under?
8, 10, 16, 25, 50 or 100 MB. 10 MB is Discord’s free limit, 16 MB is WhatsApp’s and 25 MB is the attachment limit for Gmail and Outlook. Choose Fit a file size and the resolution is lowered automatically when a long video needs it.
Which formats can I compress?
MP4, M4V and MOV (from phones, cameras and screen recorders), WebM and MKV, as long as your browser can decode the video inside. iPhone videos in HEVC need Safari, or Chrome or Edge on a Mac or recent Windows. The result is always an MP4, with H.264 video where your browser can write it.
Why does it take a while?
Every frame is decoded and encoded again, which is real work: on a recent laptop expect roughly real time or faster for 1080p, slower on a phone. Keep the tab open until it finishes. Lowering the resolution also makes it faster.
Do I need an account, and is there a watermark?
No account and no sign-up: open the page and drop a file. Nothing is added to your file, so there is no watermark or logo. It is free, and your files are not uploaded.
More video and audio tools
Video to MP4
Turn MOV, MKV and WebM files into MP4s that play everywhere. Converted on this device, never uploaded.
Trim video
Cut a clip out of a longer video without uploading it. Most cuts take seconds and keep the original quality.
Mute video
Take the sound out of a video, in seconds and without re-encoding. The video never leaves this device.
Resize video
Change a video’s resolution, from 4K down to 240p or to a width and height you choose. Resized on this device, never uploaded.
Popular conversions
Guides
- How to compress a video without losing qualityMost phone video is recorded at a far higher bitrate than the screen needs. Here is what to change, and what actually loses quality.
- How to resize a videoGetting a video down from 4K to 1080p, or to an exact width and height a platform expects, is a different setting than just compressing it. Here is how, in the browser.
- How to turn audio into a videoTo put a song, a podcast episode or a voice note on YouTube, you need a video. Here is how to make one from the sound and a single picture.