Manatee

How to compress a video for WhatsApp on a Mac

· 6 min read

WhatsApp recompresses every video sent as a normal message and refuses the ones over its media limit, which as of this writing is 16 MB on most accounts. The fix is to shrink the video yourself to a size and resolution WhatsApp will accept and not mangle, then send it; or to send it as a document, which skips recompression and allows files up to 2 GB. On a Mac, QuickTime Player’s export presets get most clips close, and Manatee’s Shrink mode lets you name the exact size.

What WhatsApp does to a video

There are two doors. Send a video as media (the camera or gallery button) and WhatsApp re-encodes it on the way out, lowering the resolution and bitrate so it loads quickly on the other end. It refuses anything over the media cap before it even starts. Send the same file as a document (the paperclip, then Document) and WhatsApp transmits the bytes untouched, with a far higher ceiling; the recipient gets a file to download rather than a clip that plays in the chat.

The limits have shifted over the years and differ by platform and region, so treat the numbers here as a starting point and check WhatsApp video limits explained for the current figures and the reasoning behind them.

The practical consequence: if you send a 40 MB iPhone clip as media, it will be refused; if you shrink it to 14 MB at 720p first, it will be accepted, and WhatsApp’s recompression will have much less to do, so it arrives looking like what you sent.

Decide which door to use

  • A short clip that people should watch inline, on the spot: compress to under the media limit and send as media.
  • A long or high-quality video where fidelity matters (a performance, a wedding toast, footage someone will edit): send as a document. It can still be large, but be kind to the recipient’s data plan and shrink it anyway if it is over a few hundred megabytes.
  • Anything both long and meant for inline viewing: trim it. Thirty seconds of the good part beats four minutes nobody watches.

Trim before you compress

Seconds are the cheapest thing to cut. Open the video in QuickTime Player, choose Edit, Trim, drag the yellow handles to the part you want, and click Trim. Then File, Save (or Export As). A 90-second clip cut to 20 seconds is already most of the way to the limit without touching quality.

Shrink with QuickTime Player

QuickTime cannot target a file size, but its presets are a reasonable first attempt for short clips.

  1. Open the video in QuickTime Player.
  2. Choose File, Export As, and pick 720p. For a clip under 30 seconds this usually lands under the media limit; for longer clips try 480p.
  3. Save it, then check the size in Finder (select the file and press Command-I).
  4. If it is still over, there is no lower preset, and exporting the export again only loses quality. Move to Manatee.

QuickTime exports a .mov. WhatsApp accepts MOV as media, but if you want to be certain it plays on every phone in the group, convert to MP4 as part of the next step.

Name the size with Manatee

Manatee’s Shrink mode is built for the “it needs to be under N megabytes” problem. You give it a number; it works out the quality that fits.

  1. Open Manatee. It is free with every feature for 24 hours (no card, no email), then $9 once.
  2. Drag the video onto the menu bar icon or into the window’s drop zone. Start from the original (or your trimmed copy), not from a QuickTime export that was already compressed; compressing twice costs quality for no gain.
  3. Choose Shrink and type the size in MB. Leave some margin: 15 for a 16 MB limit.
  4. Wait for the job to finish. The shrunk file is written beside the original, which is never modified.
  5. Check that the result plays and looks acceptable before sending.

If the source is a MOV, MKV, WebM, or something else from a download, run Convert to MP4 first so the file plays on every phone in the group. Manatee is not a video editor: it does not trim, crop, or add captions, so do the trimming in QuickTime beforehand.

Shrink is honest about the tradeoff. A 10-minute 4K video squeezed into 15 MB will look rough, because 15 MB is not enough data for that many pixels and seconds. When that happens, the answer is to trim, to send as a document, or to accept the quality. There is no setting that beats arithmetic.

Getting it from the Mac to WhatsApp

You can send directly from the Mac if WhatsApp’s desktop app or web version is signed in: drag the file into the chat and choose whether it goes as media or as a document. Otherwise AirDrop the shrunk file to your iPhone; it lands in Photos, and you send it from there as usual. AirDrop does not recompress video, so what you made on the Mac is what goes out.

One privacy note: a video recorded on a phone carries the date, the device model, and sometimes location. WhatsApp’s recompression discards most of that when you send as media, but a document goes through untouched. Manatee’s Clean mode removes it on the Mac beforehand if that matters; how to remove metadata from a video before posting it explains what is in there.

Questions

Why does WhatsApp make my video look worse even when it is under the limit?

Because it always recompresses media. The less it has to do, the better the result, so a clip that is already 720p and comfortably under the limit survives far better than a 4K file right at the edge.

Is sending as a document really uncompressed?

Yes. The bytes arrive unchanged, which is why the document limit is so much higher. The recipient has to download and open the file, and on a phone that is one more tap than an inline video.

What size should I aim for?

Under the media limit with a margin, so around 15 MB for a 16 MB cap. For long clips, trim first; for anything that cannot be trimmed, send as a document.

Does Manatee work on iPhone?

No. It is a Mac app only. Shrink on the Mac, then AirDrop the result to the phone.