Compress a PDF offline on your Mac

When you need this

An image-heavy pitch deck or scanned handout can be awkward to attach. Compression is useful when the pages you need are already in the right order and the main problem is the space occupied by pictures. Choose a quality level based on how the recipient will use the document: screen reading and detailed print review can need different image quality.

How to do it in DipperPDF

Download the DMG from GitHub Releases, open it, drag DipperPDF into Applications, and launch the app from there. The app’s README specifies macOS 14 or later. Downloading the app requires a connection, but the PDF operation works offline once the app is installed. You do not need an account, subscription, trial, or paid upgrade to use the tool.

1. Open one PDF in Compress PDF.
2. Choose Light to retain more image detail, Balanced as a starting point, or Strong to prioritize a smaller file.
3. Click Compress PDF and inspect the displayed original size, result size, and savings.
4. Check the prepared pages, then click Save PDF… and choose a separate filename.

What it does not do

Compression uses lossy image recompression and downsampling. Strong can lose fine image detail. The app keeps the original bytes as the result when recompression would increase file size. There is no guaranteed percentage reduction, target-size control, or OCR. Existing selectable text is not turned into newly recognized scan text.

A worked example

Suppose a pitch deck contains product photographs and small chart labels. Prepare a Balanced copy, look at the photographs, and zoom into the labels. If they remain useful, save that version for the attachment. If the images become too soft, prepare Light instead. Keep the original for a print workflow. If neither reduces it enough, split the deck by a sensible page count rather than promising a particular attachment size.

Check the result before sharing

Compare the saved file’s image detail with the original at the zoom level your recipient is likely to use. Look especially at photographs containing text, small labels inside charts, and thin lines in scanned diagrams. Readable selectable text does not prove that text embedded in a picture survived equally well. If a stronger setting is unacceptable, retain the gentler result or send the needed pages separately. The displayed size comparison is evidence for this particular input, not a prediction for the next PDF.

Preparing a result and saving it are separate steps. Use the prepared view to check the outcome before choosing a destination. Save under a descriptive name in a writable local folder, then reopen the saved output to check that you chose the intended result. DipperPDF saves a separate file and prevents overwriting an imported source. Keeping the original gives you a starting point if a selection or setting needs correction.

When not to use DipperPDF for this job

Use another workflow when full-resolution images are essential or the document needs an exact final byte size. A mostly text PDF may offer little opportunity for image compression. When the problem is an unnecessary appendix, removing its pages is more directly related to the job than changing image quality.

If the document needs another operation

If another operation is needed, save this result and import that saved copy into the next tool. There is no automatic chain of tasks here. Make the order deliberate: changing the page count or sequence can change which pages a later range refers to. When an input is encrypted, use Unlock PDF first with the password and permissions required by the document, then work with the authorized unencrypted copy.

FAQ