Compress a video to attach to an email
The Gmail and Outlook presets aim below the message limits, because email adds about a third to every attachment.
This browser cannot compress video here
Target: Email: Gmail, 18 MB. You can change it after adding a video. Your video stays on your device.
How it works
- Add the video you want to attach.
- Choose Email: Gmail (18 MB) or Email: Outlook (14 MB).
- Press Compress and check the size shown in the result.
- Download the MP4 and attach it to your message as usual.
Why email needs a smaller file
Email carries attachments as text, and that adds about 37% to their size. Gmail allows 25 MB per message and Outlook 20 MB, but a 25 MB video would grow past the limit once it is attached.
The Gmail preset therefore aims at 18 MB and the Outlook preset at 14 MB. Both leave room for the overhead and for the text of your message.
Gmail or Outlook?
Pick the preset of the smaller limit when you do not know what the other side uses. If the people you write to use Outlook, choose Email: Outlook. A file that fits 14 MB will also go through Gmail.
When a video is too long for email
A few minutes of video at 14 MB is already a low bitrate. For a longer video, a link to a shared folder works better than an attachment. A short summary clip with the audio removed is another option.
Questions
What are the Gmail and Outlook attachment limits?
Gmail allows 25 MB per message and Outlook 20 MB. Email encoding adds about 37%, which is why the presets are 18 MB and 14 MB.
Why not compress to exactly 25 MB?
The attachment grows by about 37% when it is encoded for email, so a 25 MB file would be refused. The 18 MB preset keeps the whole message under 25 MB.
Is the video sent to your servers first?
No. Compression happens in your browser, and the site has no server that could receive the video. You attach the finished file to your email yourself.
Which format does the attachment have?
MP4 with H.264 video and AAC audio, which opens on Windows, macOS, iOS and Android without extra software.