Compress a Video and Reduce Its File Size
Drop your video, choose WhatsApp, email, or a size in MB: it's compressed to MP4, ready to send. Nothing leaves your device.
- WhatsApp, email, Discord
- Choose the size in MB
- MP4 that plays anywhere
- 100% private
100% private — Everything is processed directly in your browser: your files, voice, and image are never sent to Chatzam's servers.
How to compress a video?
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Add the video
Drag your MP4, MOV, or WebM file into the area: the preview shows its file size, length, and resolution.
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Choose your goal
WhatsApp (under 16 MB), email (under 25 MB), Discord (under 10 MB), “Half the size”, or a custom size in MB.
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Download the MP4
Start the compression and keep the tab open: the remaining time is shown, then your smaller video is ready to download.
A smaller video, with no complicated settings
Ready-made goals
WhatsApp, email, Discord, or half the size: one click is all it takes, no need to know anything about codecs or bitrates.
Automatic calculation
The tool calculates the right bitrate for the target size and, if needed, scales the video down to 720p or even 480p.
MP4 that plays everywhere
The video is saved as MP4 (H.264 and AAC), which plays on iPhone, Android, WhatsApp, and computers.
No upload
Compression happens in your browser with FFmpeg: your personal videos are never sent anywhere.
Video too big for WhatsApp or email?
A minute of smartphone video often weighs several dozen MB, and much more in 4K. Yet WhatsApp limits videos to 16 MB, Gmail caps attachments at 25 MB, and Discord blocks files over 10 MB on its free plan. Choose the matching goal: the tool works out the right settings on its own and gives you an MP4 that fits under the limit.
Reducing a video's file size: how does it work?
A video's file size depends on its length and its bitrate, meaning the amount of data used for each second. To hit the target size, the tool calculates the possible bitrate, then lowers the resolution if needed (from 1080p to 720p, or even 480p): a 720p video stays sharp on a phone screen, whereas an over-compressed 1080p video would turn blurry and pixelated. The longer the video, the more quality you have to give up to fit into a small size: for a long video, first keep only the part you need with “Cut / Trim Video”.
Compression with no software and no upload
The video is compressed right in your browser with FFmpeg, the go-to engine for video processing: nothing to install, and no file sent to a server. A video lasting a few minutes is processed fairly quickly; a long video takes more time, depending on how powerful your device is. An estimate of the remaining time is shown: keep the tab open until the end. To keep only the audio, use “Convert MP4 to MP3”.
Frequently Asked Questions
How do I send a video that's too big for WhatsApp?
Add it and choose the WhatsApp goal: it's compressed to under 16 MB, as an MP4, and you then send it normally from the app. If it's very long, cut out the part you need first to keep better quality.
Does compression reduce quality?
A little, because making a video smaller means removing detail. On a short video, the difference is often barely visible on a phone; the smaller the target size compared to the length, the more noticeable the drop in quality.
How long does compression take?
It depends on the video's length and your device's power: a few minutes of video are processed fairly quickly, while a long video can take much longer. The remaining time is shown during processing; keep the tab open.
Which video formats are supported?
MP4, MOV (iPhone), WebM, and most common formats. The compressed video is always saved as MP4 (H.264 and AAC), the most compatible format.
Is my video uploaded to a server?
No. Everything happens in your browser; only the FFmpeg engine is downloaded on first use. The tool is free, with no account and no watermark.