Keep photo quality when sending from Mac to WhatsApp

You sent a photo through WhatsApp on Mac and it arrived looking like it had been printed and scanned twice. WhatsApp re-compresses everything you send — that’s not a bug, that’s how the platform stays fast. The trick is making sure WhatsApp’s compression starts from a better source.

Why this happens

WhatsApp’s pipeline does two things to your photo: resize and re-encode. The defaults aim for roughly 1600px on the longest edge and JPEG quality around 65-70. That’s fine for casual snaps and devastating for anything with text, fine detail, or screenshots.

The thing is, WhatsApp’s encoder hits your photo regardless of how big or perfect it was when you sent it. Sending an 8 MB original gives you exactly the same final result as sending a 1 MB pre-optimised copy — because WhatsApp re-compresses both. So the question isn’t “how big should I send?” but “how should I prepare the photo to survive WhatsApp’s re-encoding?”

The native way

Two rules of thumb:

1. Pre-resize to about 1920px on the longest edge. WhatsApp won’t enlarge it, but if it’s already at their target dimensions it won’t need to re-sample.
2. Pre-compress at high quality (90+). WhatsApp’s quality 65 re-encoding does less visible damage when the source is clean than when it’s already been through a low-quality pass.

In Preview: Tools → Adjust Size → 1920px on longest edge → File → Export → Quality 90 → Save.

From Terminal:

sips -s format jpeg -s formatOptions 90 -Z 1920 photo.heic —out for-whatsapp.jpg

Convert HEIC to JPEG in the same step — WhatsApp will re-encode HEICs to JPEG anyway, doing it yourself first gives you control.

Send as a document for true preservation

If you absolutely need pixel fidelity, attach the photo as a Document instead of a Photo in WhatsApp. From the WhatsApp Mac app, click the paperclip → Document → pick the image file. WhatsApp won’t re-compress documents — the recipient gets the file you sent, byte for byte.

The catch: it shows up as a file attachment, not an inline image preview. Recipients have to tap to view.

The faster way

For batches — sharing 20 photos from a trip, sending product shots to a buyer — Download Melt prepares them all at once.

1. Download Melt and open it.
2. Drag in the photos (or a folder).
3. Set output to JPEG, quality 90, Resize at 1920px longest edge.
4. Click Compress, then drag the output into WhatsApp.

EXIF strips automatically, which on photos sent to non-family contacts genuinely matters.

How much smaller will it really get?

Before WhatsApp’s re-encoding kicks in, your prepared photo is around 400-700 KB instead of 8-12 MB. After WhatsApp re-encodes it on the recipient’s end, the visible quality is noticeably better than sending the original — because the source was already at WhatsApp’s target size, so the re-sampling step doesn’t introduce additional blur.