Making a video small enough to send
2026-10-06
A one-minute phone video can be over 100 MB, and many email services stop at around 25 MB per message. Before converting, it helps to know what actually controls the size, because the converter changes only one of the three factors.
What decides the size of a video
- Length. Twice as long is about twice as big.
- Resolution. A 4K frame has four times the pixels of a 1080p frame.
- How hard it is compressed. This is the part a converter controls.
Content matters too. A talking head against a still background compresses far better than handheld footage of a football match, at the same settings.
What this site changes, and what it does not
| Changed by converting here? | |
|---|---|
| Compression strength | Yes. High, Medium and Small set it (CRF 20, 24, 28 for MP4) |
| Audio bitrate | Yes. 256, 192 or 128 kbps |
| Resolution | No. A 4K video stays 4K |
| Frame rate | No |
| Length | No. There is no trim tool |
So MOV to MP4 on Small will shrink most phone recordings noticeably, but it cannot perform miracles on a long 4K clip, because the two biggest factors are untouched.
Do these first
- Trim. Cutting a 60-second clip to the 15 seconds that matter removes three quarters of the file before any conversion. Every phone's gallery app can do it.
- Convert on Small. Check the size shown on the download button.
- Still too big? Try the WEBM route below, or use one of the alternatives at the end.
When you need a predictable size: WEBM
MP4 output is quality-based: the encoder uses as many bits as the picture needs, so the size cannot be known in advance. WEBM output on this site is bitrate-based, which makes the size roughly predictable from the length alone.
| WEBM setting | Video bitrate | Approx. size per minute (picture only) |
|---|---|---|
| High | 2 Mbps | 15 MB |
| Medium | 1 Mbps | 7.5 MB |
| Small | 500 kbps | 3.8 MB |
Audio adds a little on top. At 500 kbps a high-resolution video will look soft, so this suits clips where being able to send it matters more than how sharp it is. WEBM plays in Chrome, Firefox, Edge and on Android; older iPhones and some messaging apps do not play it, so check with the recipient. Use MP4 to WEBM for this.
Why the result is sometimes bigger
If the original was already compressed hard, for example a video that came through a messaging app, re-encoding it can produce a larger file. The encoder here runs in its fastest mode so that it is usable in a browser, and fast encoding is less efficient. When that happens, the original was already about as small as it will get at that resolution.
If it is still too large
- Share a link instead. Cloud drives and most phones' share sheets can send a link to the full-quality file. Nothing is lost and there is no size limit to fight.
- Record at a lower resolution next time. 1080p instead of 4K cuts the file to a fraction, and few people watching on a phone can tell.
- Use a desktop encoder for resizing. Lowering the resolution is the most effective way to shrink a video, and it is not something this site does.