Vis Exo
TOOL — VIDEO COMPRESSION
Compress a Video Online, Free In Your Browser
Most video files are far bigger than they need to be for the way they are actually watched. Dropping the resolution and setting a saner bitrate is the whole trick, and it needs no server: the file is rebuilt in your browser and handed straight back.
Resolution First, Then Bitrate
Resolution is the big lever
Halving the width and the height removes three quarters of the pixels, and the pixels are where the size lives. Going from 4K down to 1080p is usually a bigger saving than any quality setting can produce.
Then the bitrate
At a fixed resolution it is the encoder bitrate that decides both the file size and how well the picture holds up. The quality selector maps to a high, balanced or smaller-file setting.
Why compressing means re-encoding
A smaller file means new video data, so the frames are decoded and encoded again. There is no way around that — rescaling and re-quantising are exactly what re-encoding is.
Progress you can watch and cancel
A progress bar tracks how far through the clip it is, and the run can be cancelled half way without leaving a broken file behind.
Three Steps, In Your Browser
- 1
Load the video
Any MP4, MOV, WebM or MKV. The read-out describes what is inside the file first, which tells you how much room there is to shrink it.
- 2
Choose a resolution and quality
720p with Balanced is the dependable default for sharing. 480p is aggressive but fine for reference clips, and 1080p suits anything watched full-screen.
- 3
Convert and compare the sizes
The result panel reports the before and after size, so you can see what you saved rather than guessing at it.
Compress a Video on iPhone, Mac, Windows and Android
The same page works everywhere, with nothing to install. What differs is where the file comes from and where it goes.
iPhone & iPad
Compress in Safari before sending by email or messages; 720p with Balanced quality roughly halves most iPhone clips.
Mac
Screen recordings shrink dramatically at 720p, since most of the frame never changes.
Windows
Chrome or Edge compress fastest using the graphics chip; no install needed.
Android
Compress in Chrome for WhatsApp or Discord upload limits.
How Much Should You Compress?
Three options, honestly compared — including when the right answer is to convert nothing at all.
| Target | Pick it when | Watch out for |
|---|---|---|
| Lower resolution first | The file has to fit an email limit, a form cap or a slow connection. | Rescaling is the biggest saving and the most visible one. |
| Same resolution, lower quality | It only needs to be smaller without looking softer. | Saves less: quality per byte is already set by the encoder. |
| Audio only — MP3 or M4A | Only the sound matters — a lecture, an interview, a music set. | Deletes the picture; not a way to shrink a video you still need to watch. |
Compress a Video FAQ
How do I make a video file smaller?
Lower the resolution first, then pick a lower encoding quality. Both controls are on this page, and the file is rebuilt locally in your browser with no upload.
Can I compress a video without losing quality?
Only up to a point. If the file merely needs a different container, nothing is re-encoded and nothing is lost — the MOV and MKV conversions are lossless re-wraps. As soon as frames are rescaled or re-quantised, some quality is spent, and that is the trade being made.
What resolution should I pick for sharing a video?
720p is the sweet spot for most sharing: it looks clean on a phone and still plays comfortably on a slow connection. Choose 1080p when it will be watched on a monitor or a television.
How much smaller will my file get?
It depends on the source. A lightly-compressed 4K clip can more than halve on the way to 720p, while a file that is already small and low bitrate will barely move. The result panel reports the real numbers for your file.
Does compressing work on a phone?
Yes, in a recent mobile browser, though more slowly than on a laptop because phones throttle sustained encoding. A short clip is comfortable; a long one is better done on a computer.
Related Converters
MOV to MP4
QuickTime files that already hold H.264 and AAC are re-wrapped rather than re-encoded — near-instant, with nothing lost.
MKV to MP4
Matroska is the archive container, and its contents are frequently H.264 and AAC already — so the conversion is usually a lossless re-wrap.
WebM to MP4
Screen recordings and browser captures arrive as WebM, which iPhones and QuickTime will not open. This turns them into H.264 MP4s.
HEVC to H.264
Modern phones record H.265 to save space, then half the world will not play it. This converts it to H.264, the codec everything decodes.
Convert it, then track something in it
Vis Exo adds blob tracking, pose skeletons, trails, LUT grades and captions to the finished MP4 — free, and entirely in your browser.