Compress Video
Make a video small enough to send — see the new size before you start.
Using toolbook means you agree to our Terms and Privacy Policy.
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
- Any length is fine. 1080p works on any device that plays it. 4K can be heavy for a browser — shrinking it to 1080p fixes that, and is usually what you want anyway.
Your files stay on your device
How to use it
Drop a video, pick a frame size and quality, and check the new file size before you start. You get an MP4 that plays everywhere. Your video stays private.
Phone videos are huge — a one-minute clip can be 150 MB. Drop yours onto the box above, and the starting settings (720p, balanced quality) usually bring that down to around 12 MB.
Two ways to shrink it: a smaller frame size (like 720p or 480p) keeps the picture sharp but smaller, and lower quality keeps the size but looks softer, especially in fast motion. The new file size updates as you change them.
It takes about as long as the video is — a 10-second clip is nearly instant, a 10-minute one is a proper wait. A smaller frame size makes it faster too.
You always get an MP4 that plays on every phone, browser, and messaging app.
FAQ
How small can I get a video?
A one-minute 1080p phone video of around 150 MB usually ends up near 12 MB at 720p, or 5 MB at 480p. The new size shows before you start.
How long does it take?
About as long as the video. Smaller frame sizes are faster.
Will it lose quality?
A little — that’s how it gets smaller. “High” looks very close to the original; “Tiny” is for strict size limits.
Why did my file get bigger?
The original was already well compressed. Try a smaller frame size instead.
It says my browser can’t make videos. What now?
Try Chrome, Edge, or Safari. Firefox on Linux often can’t create videos.
Can I compress a 4K video?
Usually — and shrinking it to 1080p at the same time helps a lot.
How it worksFor the curious
The browser’s own hardware video encoder (WebCodecs) does the work: the file is read off disk in pieces, decoded, scaled, re-encoded at a lower bitrate, and written as MP4 with H.264 video and AAC audio — not the most efficient pairing (AV1 is smaller), but the one that plays everywhere.
Reducing frame size discards pixels (720p has 44% of 1080p’s), each keeping its detail. Reducing quality keeps every pixel and spends fewer bits on them, showing as softness and blocking around motion.
The expected size is length × bitrate plus container overhead, calculated rather than measured — a live preview would take as long as the job. Real files land within a few percent, and still scenes come out smaller. The bitrate is capped at the source’s own, and the tool warns when compressing an already-efficient file is not worth it.
A decoded 4K frame is about 33 MB, so 4K is where a tab starts to strain. Browsers without a video encoder — usually Firefox on Linux — are detected and told so.