Compress video — a smaller file at the same resolution

Phone clips and stock footage are recorded at a much higher bitrate than they need, which is why a ten-second clip can be thirty megabytes in size. Add a video and it is re-encoded in your browser at a more sensible bitrate — often around ninety percent smaller, while the picture keeps its original dimensions. There is no upload, no queue and no watermark.

  1. Your video

    Drop a video here — or click to choose

    MP4MOVWEBMMKV

    Your files are never uploaded — everything runs on your device.

  2. Quality

  3. Smaller file

How to compress a video

  1. Add the video

    Drag in an MP4, MOV, WebM or MKV, or click to choose one. It loads straight into your browser — your files are never uploaded.

  2. Pick a quality

    Balanced suits most clips. High keeps more detail in fast motion, Smallest file squeezes hardest for a strict attachment limit. The resolution is untouched whichever you pick.

  3. Compress and download

    Encoding runs on your device and shows its progress. The compressed video plays right there in the page, with its old and new size side by side, so you can check it before you keep it.

What you get

The picture stays the same size

Most video compression tools reduce the picture dimensions, because using fewer pixels is the simplest route to a smaller file. This tool keeps the resolution unchanged and reduces the bitrate instead, so a 1080p video is still 1080p when you send it.

Your audio is kept, not re-encoded

Where the file it writes can hold the original audio track, it is copied across byte for byte — no second generation of loss on a track that made up well under one percent of the original file. Where it cannot, the tool says so on the result instead of quietly swapping it.

You see the saving before you keep it

The result card plays the compressed video and shows the old size next to the new one. If a file comes out no smaller — which happens with video that was already compressed properly — you are told that rather than handed a pointless download.

What it runs on

No AI model and no server. The container is read and written by mediabunny, and the encoding is done by WebCodecs, the video encoder already built into your browser — which is why it takes seconds rather than minutes.

Frequently asked questions

How much smaller will my video get?
On footage straight from a phone or a stock library, usually around ninety percent — a 31 MB 1080p clip came out at 2.6 MB on the Balanced setting in our own testing. Video that has already been compressed properly will shrink far less, and if it comes out no smaller at all the tool tells you instead of offering the download.
Does it lose quality?
Yes — it re-encodes the video at a lower bitrate, and that throws some detail away. On ordinary footage the difference is hard to see, because the original was carrying far more data than the picture needed. Fast motion and fine grain are where it shows first, so pick High for those.
Does the resolution change?
No. A 1080p video stays 1080p and a 4K video stays 4K. Only the bitrate changes.
What happens to the audio?
Wherever possible it is copied across untouched, so there is no extra generation of loss. In Firefox the output has to be WebM, which cannot carry AAC at all, so the AAC audio in a typical MP4 is re-encoded to Opus. Audio that WebM can already hold is copied like anywhere else, and the result card always says which of the two happened.
Is there a file-size limit?
There is no limit imposed by a server, because your video is never uploaded to one. The practical ceiling is your device's memory, since the compressed video is assembled there before you save it. A very long file on a phone is where that runs out first.
Why is it slower in Firefox?
Chrome and Edge can encode H.264 using your hardware encoder, which takes a couple of seconds. Firefox's built-in encoder cannot produce H.264 at all, so it writes VP9 in software instead — the same clip can take tens of seconds. The file is just as good; it only takes longer to make.
How can I check that my video is not being uploaded?
Open your browser's developer tools, switch to the Network tab, and compress a video with it open. You will see no request carrying your video — and no model download either, because there is no model: mediabunny reads and writes the container and the encoding is done by WebCodecs, the encoder already built into your browser. Then sort that list by size: the largest thing the page sends is a few kilobytes of analytics, nowhere near the size of your video. This page loads analytics and advertising like most websites do, which is why the claim is scoped precisely: your files are never uploaded.

Only need the sound? Pull it out with video to MP3. Want a short loop for chat instead? Use video to GIF.