Compress a video for email
Your files are processed on your device. We never upload them.
Video is read and written with Mediabunny, under the Mozilla Public License. Browsers without their own AAC encoder use FFmpeg's, under the GNU LGPL.
How to compress a video for email
- 01A ▸Choose your videos, or drop them on the page.
- 02A ▸The size is already set to 18 MB, which fits after email adds its overhead.
- 03A ▸Select Compress, then download each video and attach it to your message.
About email
The limit
Gmail accepts 25 MB of attachments per message on personal accounts; Outlook.com accepts 20 MB. Email encodes attachments as text (Base64), which makes them about 37% larger in transit, so the video itself must be smaller: 18 MB fits Gmail, and 14 MB fits Outlook. A phone records 18 MB in under ten seconds of 1080p.
- Google: Gmail attachment size limits (checked 2026-11-13)
- Microsoft: attachment size limit in Outlook (20 MB for internet email accounts) (checked 2026-11-13)
How the tool gets there
The tool divides 18 MB by the video's length to get the bits a second it can spend, keeps 6% back because encoders overshoot, and gives the sound 64 to 128 kbps. If the picture would look blocky at the rest, it is made smaller (1080p, 720p, 540p, and so on). A result still over the size gets one more, lower try.
What fits in 18 MB
For a 1080p phone video at 30 frames a second, worked out with the same arithmetic the tool uses:
| Length | Bitrate (picture and sound) | From 30 fps video | From 60 fps video |
|---|---|---|---|
| 0:15 | 8,934 kbps | 1080p at 30 fps | 1080p at 60 fps |
| 0:30 | 4,467 kbps | 1080p at 30 fps | 1080p at 30 fps |
| 1:00 | 2,233 kbps | 720p at 30 fps | 720p at 30 fps |
| 2:00 | 1,117 kbps | 540p at 30 fps | 540p at 30 fps |
| 5:00 | 447 kbps | 360p at 30 fps | 360p at 30 fps |
| 10:00 | 223 kbps | 240p at 30 fps | 240p at 30 fps |
Measured
Our one-minute 1080p sample at 30 frames a second (H.264 at 8 Mbps with AAC sound, 61.1 MB; a synthetic test pattern, which is easier to encode than real footage), compressed in Chrome on a laptop. Phone timings are still to be measured.
| One minute of 1080p, 61.1 MB | 16.8 MB at 1280 × 720, in 5.3 seconds |
|---|---|
| Size in the email (Base64) | about 23 MB, under Gmail's 25 MB |
| Time on phones | still to be measured |
If it doesn't fit
- Trim the video to the part that matters first; a shorter video keeps more quality.
- For Outlook, enter 14 MB; for a work account, ask what your organisation allows.
- For long videos, share a link from your own cloud storage instead of attaching the file.
Other options
- Compress video to 10 MB: for forms and portals with a 10 MB cap.
- Trim video: to send only the part that matters.
- Compress video: to choose a strength instead of a size.
Questions
Are my videos uploaded?
No. Your files are processed on your device. We never upload them.
Why 18 MB when Gmail allows 25 MB?
Email turns attachments into text (Base64) for sending, which makes them about a third larger. An 18 MB video becomes about 24 MB in the message, just under Gmail's 25 MB. Outlook.com's limit is 20 MB including that growth, so enter 14 for Outlook.
What happens if I attach a larger video in Gmail?
Gmail turns it into a Google Drive link instead of an attachment. That works too, but the video is then stored on Google's servers.
Can I send several videos in one email?
The limit is for the whole message. For two videos, compress each to half the size, such as 9 MB.
Will the person I send it to be able to play it?
Yes. It's an MP4 with H.264 and AAC, which every phone and computer plays.