How to compress a video to email it from a Mac

Most email providers cap attachments somewhere between 20 and 25 MB, and a video from a phone crosses that line in well under a minute of footage. To get one through, shrink it on the Mac before attaching: a QuickTime export at 720p for short clips, or Manatee’s Shrink mode when you want to name a size such as 18 MB and have the app find the quality that fits. For anything longer than a couple of minutes, Mail Drop or a shared link is the better tool, and Apple Mail offers the first one for free.

The numbers that matter

The widely used providers land close together: 25 MB for one, 20 MB for several others, with corporate mail servers frequently lower. The number that catches people out is the encoding overhead: attachments are converted to text for transmission, which inflates them by about a third. A 24 MB file becomes roughly 32 MB on the wire and bounces from a 25 MB server. So the real target for a 25 MB limit is about 18 MB, and for a 20 MB limit about 14 MB.

Email attachment size limits by provider keeps the current figures for each provider.

Option 1: let Mail Drop carry it

If you use Apple Mail with an iCloud account, you may not need to compress anything. Attach a large file and Mail offers to send it via Mail Drop: the video is uploaded to iCloud, the recipient gets a download link that works in any mail client, and the link expires after 30 days. Mail Drop handles attachments up to 5 GB, and it does not count against your iCloud storage.

1. In Mail, write the message and attach the video as usual.
2. When you click Send, Mail asks whether to use Mail Drop. Accept.
3. The message sends immediately; the upload continues in the background.

The catch is the recipient’s side: some corporate mail systems strip or quarantine links, and a download link is one more step than an inline attachment. For a quick clip to a family member, compressing and attaching is often friendlier.

Option 2: trim and export with QuickTime Player

Seconds are the cheapest thing to cut, and every Mac can do this.

1. Open the video in QuickTime Player.
2. Choose Edit, Trim, drag the yellow handles to the part worth sending, and click Trim.
3. Choose File, Export As, and pick 720p. For a clip under 30 seconds this usually lands comfortably under 18 MB.
4. Save, then select the file in Finder and press Command-I to check the size.

If it is still too large, do not export the export. A second pass through a lossy encoder degrades the picture for a modest size gain, and the loss compounds with every pass. Go back to the trimmed original and use the next option.

Option 3: name the size with Manatee

Manatee’s Shrink mode exists for exactly this sentence: “it has to be under 18 MB.”

1. Open Manatee. It is free with every feature for 24 hours, no card or email, then $9 once.
2. Drag the video (the trimmed version, if you trimmed) onto the menu bar icon or into the window’s drop zone.
3. Choose Shrink and type the target in MB. Use the overhead-adjusted number: 18 for a 25 MB limit, 14 for 20 MB.
4. The shrunk file is written beside the original. Manatee never modifies the source, so you can try a different number without losing anything.
5. Play the result before attaching it.

Shrink works on MOV, MP4, and the rest of Manatee’s video inputs, so an iPhone clip, a screen recording, or a download all go in the same way. If the recipient might be on Windows or an older device, run Convert to MP4 as well; H.264 vs HEVC explains why an iPhone’s default video sometimes refuses to play elsewhere.

Manatee cannot make arithmetic go away. Four minutes of 4K in 18 MB will look poor, and the app will deliver what 18 MB can hold rather than pretend otherwise. At that point trim more, or send a link.

Option 4: send a link instead

For a video longer than a few minutes, a link is kinder to everyone. Upload to whatever cloud storage you already use, set sharing to anyone with the link (or to the recipient’s address), and paste the link into the message. The recipient streams it rather than downloading, you can fix the video later without re-sending, and there is no size limit to dance around. The cost is the one Mail Drop shares: a link can be blocked by cautious mail filters, and it expires or breaks when you move the file.

Before you hit Send

1. Play the compressed file start to finish. A clipped ending or silent audio is easier to fix before the recipient sees it.
2. Consider what travels with it. Phone video carries the device model, the date and time, and often GPS coordinates. If the email is going beyond friends and family, Manatee’s Clean mode strips that; how to remove metadata from a video before posting it shows what is in there.
3. Check the final size once more in Finder. Mail shows the attachment size in the message window too.

Questions

What size should a video be to email it?

Under 18 MB to be safe with a 25 MB provider, under 14 MB for a 20 MB one. The gap covers the encoding overhead that email adds to every attachment.

Why did my 22 MB video bounce from a 25 MB limit?

Encoding overhead. Attachments grow by about a third in transit, so 22 MB became roughly 29 MB and exceeded the limit. Aim lower.

Will the recipient be able to play it?

An MP4 plays on effectively anything. A MOV from an iPhone usually plays but can fail on older Windows machines, particularly if it was recorded in HEVC. Converting to MP4 helps; if the original was HEVC and the recipient still cannot play it, the H.264 vs HEVC post above explains the remaining options.

Does compressing the video remove the location data?

Not by itself. Shrinking changes the picture, not the metadata. Use Clean mode, or accept that the recipient could read where the video was shot.