How to compress a video for email
- Choose the videos to compress (up to 20).
- Keep Compression mode on Target size and set the size in MB (20 MB is preset).
- Optionally lower Maximum resolution for long videos.
- Select Compress and download the smaller files.
Worked example
For a 2-minute clip with 128 kb/s sound, a 20 MB target (20 × 1,048,576 bytes, with 2 percent kept for the container) leaves about 1,242 kb/s for the video.
Formats and limits
| Input | MP4, MOV, WebM, MKV |
|---|---|
| Output | MP4, WebM |
| Limits | Input files up to 4 GB; the compressed file is built in memory. Codec availability depends on the browser. Needs a browser with WebCodecs (current Chrome, Edge, Safari 17+ or Firefox 130+). Other browsers are told so before any work starts. |
| Engine | Mediabunny conversion with WebCodecs; bitrate derived from the target size and duration, with a second pass if the first lands above the target |
Limitations
- Very long videos may not fit 20 MB at a watchable quality; a link to a shared file can be the better choice.
- Encoders do not hit a size exactly; the tool re-encodes once if the first result is too large.
- Codec availability depends on the browser.
- Needs a browser with WebCodecs: current Chrome or Edge, Safari 17 or later, or Firefox 130 or later. Other browsers are told so before any work starts.
Questions
What size should a video be for email?
Check your email service's attachment limit and set a target below it. If the message is still refused, set a lower target, such as 15 MB, and compress again.
Will the video look worse?
To fit a smaller size the video is encoded at a lower bitrate, so fine detail is lost. Long videos need a very low bitrate to reach 20 MB; lowering the resolution to 720p or 480p keeps them clearer.
What if the result is still too big?
If the first encode is over the target, the tool encodes once more at a lower bitrate. If it is still above, the result says so; lower the resolution or the frame rate and try again.
Privacy
Runs on your device. Files and text are processed in this browser tab and are not uploaded.
This page opens the Video compressor ready for this task. See the privacy policy for how toolsdocks handles data.