Compress a PDF on Mac

Get any file to the size you need. Privately.

1 Open this page on that device and wait until the tools are on-device.2 Add the PDF from local files and compress. A size page can set a goal if you need one.3 Save the download with the system sheet. That sheet is the operating system, not an upload by this app.

About this tool

Any current Mac browser can run this page. Drop the PDF from Finder. Preview’s export is also local if you prefer it. This page does not send the file to a cloud because you compressed it.

Compress a PDF on Mac stays on this device. The download is the copy you keep, and Weesize does not store a second one. Close the tab when you are finished and the bytes are gone.

  • No upload: the same page runs on the phone or the computer, so you do not switch to a server tool per device.
  • Speed: the file does not travel to a server and back, so the wait is only the work itself.
  • Quality: the original is kept when the new file would be worse or is not actually smaller.
FAQ
Does “Compress a PDF on Mac” upload my file?

Compress a PDF on Mac reads the file in this tab. There is no upload step and no account.

What will “Compress a PDF on Mac” actually change?

Compress a PDF on Mac does not post the PDF. A later share-sheet action is the operating system, and you can see it.

When is “Compress a PDF on Mac” the wrong job?

For Compress a PDF on Mac, do not switch to a store app that demands an account before it will shrink the same file.

How do I check the result of “Compress a PDF on Mac”?

After Compress a PDF on Mac, read a page on the device, then try airplane mode for a second compress once the page is ready.

Can I run “Compress a PDF on Mac” with Wi-Fi off?

Load this page, then turn Wi-Fi off and run Compress a PDF on Mac again. A finished result is the proof that the file was not sent anywhere.

Last updated 2026-09-27.