Compress Video
Get a video under a size limit, with the expected size shown before you start.
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or drag it here
MP4, MOV, WebM, or MKV
- Takes
- MP4, MOV, M4V, WebM, and MKV. AVI, WMV, and FLV are refused — no browser can demux them, so there is nothing to be done here but say so.
- Size
- The file is read off disk in pieces and only a frame or two is ever decoded at once, so length is cheap; what costs memory is frame size. A 1080p clip is comfortable on any machine that plays one. 4K is where a tab starts to struggle, and scaling down to 1080p is both the fix and usually what you wanted. Nothing is uploaded, so the only ceiling is your own browser's.
Your file never leaves your browser during processing
How it works
To compress a video, drop it onto this page, choose a frame size and quality level, and check the expected size shown next to the button before you commit. The video is re-encoded by your own browser and nothing is uploaded.
Your browser already contains a video encoder — the same hardware one it uses for video calls — and this page hands your file to it. The video is read off disk a piece at a time, decoded, scaled if you asked for that, re-encoded at a lower bitrate, and written back out as an MP4. Nothing is uploaded, and the counter under the tool watches the network during the whole process and stays at zero bytes sent.
There are two controls because there are two genuinely different ways to make a video smaller, and they are not interchangeable. Reducing the frame size throws away pixels: a 1080p clip at 720p has 44% as many, and every one of them keeps its detail. Reducing the quality keeps all the pixels and spends fewer bits describing them, which shows up as softness and as blocking around fast movement. For most files that are simply too large to send, dropping to 720p at the balanced quality is the answer, and it is what the page starts on.
The expected size is shown before you commit and updates as you change the settings, but it is calculated rather than measured — length multiplied by bitrate, plus a little for the container. The image tools show a measured size because re-encoding a photograph takes milliseconds; re-encoding a two-minute video takes about two minutes, so a live preview would be the job rather than a preview of it. In practice the real file lands within a few percent, and a static scene comes out under the estimate because there is less to describe.
The output is always an MP4 holding H.264 video and AAC audio. That is not the most efficient combination available — AV1 would make a smaller file — but it is the one that plays on every phone, every browser, and every messaging app without asking anything of the person you send it to, which is the entire point of making the file smaller in the first place.
One case the page warns about rather than hides: if your file is already efficiently compressed, these settings can produce something the same size or larger. The tool never spends more bits than the source has, and it tells you when the numbers say the exercise is not worth it. Making a video smaller is only possible when there is redundancy left to remove.
FAQ
Is my video uploaded anywhere?
No. The whole conversion runs in your browser using its own video encoder, and the network counter under the tool monitors activity during processing and stays at zero bytes sent. There is no server involved, which is also why there is no file size limit.
How small can I get a video?
That depends on its length and how much movement it contains, and the expected size is shown before you commit so you can try settings without waiting. As a rough guide, a one-minute 1080p phone video of around 150 MB usually lands near 12 MB at 720p on the balanced setting, and near 5 MB at 480p.
How long does it take?
Roughly the length of the video on most machines, because your browser has to decode and re-encode every frame. A ten-second clip is nearly instant; a ten-minute one is a real wait. Choosing a smaller frame size makes it faster as well as smaller.
Will the video lose quality?
Yes — that is how it gets smaller. Every frame is decoded and re-encoded, so this costs a generation of quality even at the highest setting. The four quality levels are honest about where that becomes visible: "High" is close to the original, and "Tiny" is for when a hard size limit matters more than how it looks.
Why did the file get bigger?
Because the original was already compressed harder than the settings you chose. Spending more bits does not recover detail the earlier encode threw away, so you get a larger file holding the same picture. The tool caps the bitrate at the source's own and warns you when the numbers say compressing is not worth doing.
What formats can I compress?
MP4, MOV, M4V, WebM, and MKV, holding H.264, HEVC, VP9, or AV1 video. The result is always an MP4. AVI, WMV, and FLV cannot be read in a browser at all and are refused by name rather than failing partway through.
It says my browser has no video encoder. What now?
Video encoding uses the encoder built into your browser and operating system, and not every combination provides one — Firefox on Linux is the usual case. Chrome, Edge, or Safari will normally work on the same machine. Converting between containers still works everywhere, because that copies the video across rather than re-encoding it.
Can I compress a 4K video?
Usually, and scaling it down to 1080p at the same time is both the fix for the size and easier on your machine. 4K is where a browser tab starts to strain, because a single decoded frame is about 33 MB. If a tab runs out of memory, that is your browser's ceiling rather than a limit set here — nothing was uploaded.