You can reduce a PDF without buying Adobe Acrobat. The right method depends on whether you already have a PDF or still have the source images. QuickWebTools can prepare smaller images, create PDFs, merge them and extract pages; it does not currently provide a dedicated compressor for an existing PDF.
Choose a method for the file you have
| Starting point | Useful approach | What to check |
|---|---|---|
| Existing PDF on a Mac | Export a copy from Preview with a reduced-size filter | Small text and diagrams remain readable |
| Existing PDF on Windows | Use the offline PDF24 Creator compression tool | Choose the installed desktop app rather than the upload-based website |
| Original photos or scans | Reduce image size before creating a new PDF | Page order, orientation and readable text |
| Only a few pages are needed | Extract those pages with the PDF Splitter | This removes pages; it is not compression |
Compress an existing PDF on macOS
- Open the PDF in Preview.
- Choose File, then Export.
- Choose the Reduce File Size option in the Quartz Filter menu when available in your macOS version.
- Save to a different filename so you keep the original.
- Compare file size and inspect representative pages at a readable zoom.
Apple notes that a smaller PDF can have lower image quality. If the result blurs a scan or a diagram, return to the original and choose a different export method or less aggressive settings. See Apple's Preview instructions.
Compress an existing PDF on Windows
PDF24 Creator is a free installed Windows application with a PDF compression tool that works offline. Open the compression tool, select your PDF, adjust the available quality and resolution controls, and save a new copy. Compare the output with the original before sharing it. The desktop application and the online PDF24 Tools website have different processing models.
Create a smaller PDF from images
- Start with the original JPG or PNG images rather than screenshots of an existing PDF.
- Use the Image Compressor to create JPEG copies with a quality setting you can inspect. It processes the image data in your browser.
- Use JPG to PDF to assemble those images into a new PDF.
- Compare the final size and inspect every page that contains small text.
This creates an image-based PDF. It will not preserve a source document's searchable text, form fields, bookmarks or digital signatures. It is appropriate for photos or scans when those features are not required. Rebuilding a text PDF as images can make it larger and less accessible.
What splitting and merging actually do
The PDF Splitter extracts selected pages. It can make a smaller attachment when the recipient does not need the entire document. The PDF Merger combines documents. Neither tool promises to recompress embedded images or reduce the size of the complete original.
Measure the result instead of expecting a fixed percentage
A photo-heavy scan may shrink more than a text-only PDF. An already optimized document may not shrink at all. There is no guaranteed reduction percentage.
For example, reducing a 12 MB file to 4 MB saves 8 MB, or about 67%. That is an illustrative calculation, not a measured result from these tools. Check the upload limit of the destination and compare both file size and readability.
Why Save as PDF is not a dependable compressor
Browser print dialogs do not provide consistent PDF image-compression controls. Printing a document to PDF can change layout, links or interactive features, and can increase file size. Use a tool with explicit compression settings when you need to optimize an existing PDF.
Before replacing the original
Check page count, page orientation, readable small text, searchability and any forms or signatures you rely on. Keep the original when the exported copy does not preserve those features. Choose a local processing method when you want the document to stay on your device.