How to Compress a PDF and Reduce File Size
Large PDF files are inconvenient to email, slow to upload, and sometimes rejected by submission portals with file size limits. Compression reduces the file size while keeping the document readable.
This guide explains what makes PDFs large and how to compress them for free using PDFEverything.
Why are some PDFs so large?
The most common cause is high-resolution images embedded in the file. A scan at 600 DPI or a photo placed in a Word document before exporting can add megabytes per page.
Other contributors include:
- Embedded fonts: Full font subsets add data, especially for documents with many font variants.
- Unused objects: Some PDF generators leave hidden deleted objects in the file.
- Multiple layers or annotations: Interactive elements add overhead.
How PDF compression works
The tool reduces file size primarily by resampling embedded images to a lower resolution and re-encoding them with more efficient compression. Text and vector content are generally not affected — they remain sharp at any zoom level.
Step-by-step: compressing a PDF
1. Open the Compress PDF tool
Go to PDFEverything — Compress PDF.
2. Upload your PDF
Drag and drop the file or click to browse. The tool analyses the file in your browser.
3. Choose a compression level
Select the level that matches your needs:
- Low compression — minimal quality reduction, moderate size saving. Good for documents where image clarity is important.
- Medium compression — balanced. Suitable for most sharing and email use cases.
- High compression — maximum size reduction. Some image quality loss. Best when file size is the priority.
4. Download the compressed PDF
The tool processes everything locally and offers the result for download. You will see the size reduction before downloading.
When to use each level
| Use case | Recommended level | |---|---| | Printing a report | Low | | Emailing a document | Medium | | Uploading to a portal with a 5 MB limit | High | | Archiving a scanned document | Medium |
What stays the same
Text, headings, links, and vector graphics are unaffected by image compression. The document structure, page count, and layout remain identical.
Compression runs entirely in your browser — your PDF is never uploaded anywhere.