Windows doesn't include a built-in PDF compressor the way Mac has Preview's Quartz filter, so the options here are either browser-based tools or desktop software. For most people the browser route is the better starting point โ it's faster to set up, produces good results, and doesn't require installing anything.
Browser-Based Compression
Open Chrome or Edge, go to WukongPDF, and use the PDF Compression tool. Upload the PDF, let it process, and download the result. For a typical business document with embedded images, expect 50-70% size reduction. For a text-only document the reduction is smaller but still meaningful โ often 20-40% just from removing redundant data and optimizing the file structure.
The browser approach works on any Windows version and doesn't depend on any particular software being installed. The main limitation is upload size โ very large files (over 100MB) may hit browser tool limits, in which case desktop software handles them better.
Using Microsoft Word's Export Settings
If the PDF was originally a Word document and you still have the .docx file, re-exporting with lower image quality settings is often more effective than compressing an already-exported PDF. In Word: File โ Save As โ PDF, then click Options and look for a picture quality or optimization setting. Choosing "Minimum size" or "Standard" instead of "High quality" reduces the output significantly for image-heavy documents.
Before exporting, also run Word's built-in image compression: select any image in the document, go to Picture Format โ Compress Pictures, choose your target resolution (150 DPI is fine for most documents, 96 DPI for anything that's only ever viewed on screen), and apply to all images in the document. This reduces the image data before it ever reaches the PDF export stage.
Print to PDF as a Compression Method
Printing an existing PDF to Microsoft Print to PDF sometimes reduces file size, because the print driver re-renders the content and creates a fresh PDF rather than preserving the original's internal structure. The effect is unpredictable โ sometimes significant, sometimes barely any reduction โ and it can rasterize vector content, which affects text sharpness. It's worth trying if other methods aren't available, but don't rely on it as your primary compression approach.
Desktop Software for Large or Recurring Compression Jobs
For regularly compressing large volumes of PDFs on Windows, PDF-XChange Editor has a capable optimization feature in its free tier that handles batch compression without file size limits. Adobe Acrobat Pro's Save As Optimized PDF provides the most granular control โ separate settings for image downsampling, font subsetting, and removing embedded data โ but requires a subscription. For most individual users, the browser tool covers enough ground that desktop software is only worth installing if you're dealing with very large files or processing many documents at once.