How to Compress a PDF on Mac (All Methods)

Mac users have several options for compressing PDFs — some built directly into macOS, others available online for free. Here's every method explained, with a clear comparison to help you choose.

Method 1: Preview (Built-in, Free)

Preview is macOS's default PDF viewer, and it includes a basic compression option through its export feature.

1. Open your PDF in Preview (double-click, or right-click → Open With → Preview).
2. Go to File → Export as PDF.
3. Click the Quartz Filter dropdown at the bottom of the save dialog.
4. Select "Reduce File Size" from the list.
5. Choose a save location and click Save.

Method 2: ColorSync Utility (Built-in, Free)

ColorSync Utility gives you more control than Preview and is also included with every Mac.

1. Open ColorSync Utility (find it via Spotlight: press Cmd+Space and search "ColorSync").
2. Click Filters in the toolbar.
3. You can create a custom filter — click the "+" button to add one and adjust the image compression quality settings manually.
4. Once your filter is set up, open your PDF in Preview and use it via File → Export as PDF → Quartz Filter → your custom filter.

This method gives you more control, but the interface is technical and not user-friendly for most people.

Method 3: Free Online Tool (Recommended)

For the best balance of ease, quality control, and results, an online PDF compressor like compress-pdf.cc is the best option for most Mac users.

1. Open compress-pdf.cc in Safari, Chrome, or Firefox.
2. Drag your PDF onto the upload area or click to select it.
3. Choose your compression level — Balanced is recommended for most documents.
4. Click Compress PDF and download your file.

This method works on every Mac without any setup, and gives you explicit control over the quality/size trade-off through three clearly labelled levels.

Method Comparison

• Preview: Quick and built-in, but limited quality control. Can degrade images significantly.
• ColorSync: More flexible but technically complex. Better for power users.
• Online tool (compress-pdf.cc): Easiest to use, best quality control, works on all Mac versions, no setup required.

For most Mac users, an online tool is the most practical choice for occasional PDF compression. If you compress PDFs daily, a desktop application like PDF Squeezer or Adobe Acrobat offers more automation options.