What makes a video file big?
A video's size depends on three things: how long it is, its resolution (how many pixels each frame has), and its bitrate (how much data is used for each second). Modern phones film in 1080p or 4K at very high bitrates, often 15 to 50 megabits per second, so a one-minute clip can be 100 MB or more. That's far more detail than you need to watch it on a phone screen or send it in a chat.
How to choose the settings
| Resolution | Best for | Typical bitrate | Per minute |
|---|---|---|---|
| 1080p | Watching on a laptop or TV | 4–6 Mbps | 30–45 MB |
| 720p | Phones, WhatsApp, email, websites | 2–3 Mbps | 15–22 MB |
| 480p | Small attachments, slow connections | 1 Mbps | 7–8 MB |
| 360p | Smallest possible file | 0.5 Mbps | 4–5 MB |
Medium quality at 720p is the best starting point: on a phone it looks almost the same as the original and is usually 70–90% smaller. If you need to fit a size limit, type it in the target size box and the tool works out the bitrate for you. Keep in mind that a very low target for a long video will look blocky.
Common size limits
- Email attachments: usually 20–25 MB (Gmail and Outlook).
- Discord: 10 MB on free accounts.
- WhatsApp: compresses videos itself, but sending a smaller file is faster and keeps more control over quality.
Limits change from time to time, so check the app if a file is rejected.
Why does it take as long as the video?
Desktop video software can compress faster than real time because it runs a dedicated encoder. A web page can't do that without uploading your file, so this tool uses your browser's built-in video recorder: it plays the video once in the background and records it again at the new size and bitrate. A 3-minute video takes about 3 minutes. The benefit is privacy and no upload wait. Keep the tab open and visible until it finishes, because some browsers slow down background tabs.
MP4 or WebM?
Safari and recent versions of Chrome save an MP4 file, which plays everywhere. Other browsers save WebM, an open format that plays in Chrome, Firefox, Edge, Android, VLC and on most websites, including YouTube. If you need MP4 specifically for an older device, use Safari or an up-to-date Chrome.
Tips for the smallest file that still looks good
- Cut the parts you don't need first with the video cutter. A shorter video is the easiest saving.
- Remove the sound if it isn't needed, such as for a screen recording or a product clip on a website.
- Videos with lots of movement (sports, shaky phone footage) need more bitrate than calm ones (talking heads, slides).
Frequently asked questions
How can I reduce the size of a video?
Lower its resolution (for example 1080p to 720p) and its bitrate. Choose those settings above and press Compress video. A 720p medium-quality video is usually 70–90% smaller than a phone original.
How do I compress a video to 25 MB for email?
Type 25 in the target size box. The tool sets the bitrate so the finished file comes out just under 25 MB.
Is my video uploaded?
No. The video is re-recorded inside your browser, on your device. It is never sent to a server.
Why is compression slow?
The browser plays the video once to re-record it, so it takes about as long as the video. Keep the tab open until it finishes.
Will the compressed video have a watermark?
No. There is no watermark, no sign-up and no limit on how many videos you compress.
Last updated October 2026 · More video & audio tools